SACAGAWEA
Sacagawea (Sacajawea) was born around 1788 in a Shoshone tribe in the Rocky Mountains of what is now Idaho. She was taken from this tribe by an Hidatsa raiding party around the age of eleven, and then later sold into slavery to Missouri River Mandans near Bismark, ND. It was from here, at the age of fifteen, that she was sold her to Toussaint Charbonneau, a French-Canadian fur trader, making her one of at least two wive's. In November 1804, Meriwether Lewis and William Clark, appointed by President Thomas Jefferson to chart a passage way through the western territories and Pasific Northwest to the Pacific Ocean, arrived in the area with the Corps of Discovery and built Fort Mandan. Soon after, on February 4, 1805, Sacagawea gave birth to her son Jean-Baptiste Charbonneau. About this time, Lewis and Clark hired Charbonneau to act as a guide and interpreter for their expedition, but the explorers were likely equally, if not more, interested in having Sacagawea accompany them as well. Because she was Shoshone, she knew several Indian languages and would proove to be indispensable on their journeys. Lewis and Clark knew that they would have to buy horses from the Shoshone in order to cross the Bitterroot Mountains and complete their expedition - Sacagawea could help them with this. The 33-member expedition left Fort Mandan in April of 1805, with Charbonneau, Sacagawea, and infant Jean-Baptiste strapped to her back as well. Sacagawea prooved not only to be indispensible in purchases horses from her Shoshone (coincidentally, from her long-lost brother Chief Cameahwait), but in numerous other areas as well. She was extremely familiar with the the territory the expedition traversed, and knew much about edible and medicinal plants and roots of which they could take advantage. More importantly, Sacagawea and her infant acted as a sign of peace for the military and scientific expedition. Because Native Americans knew that war parties were never accompanied by a woman and infant, the response was curiosity rather than hostility. Due greatly to Sacagawea's presence, no member of the expedition was lost to hostility - amazing considering most Native Americans at that time had never even seen a white man. At one point during the expedition, a canoe she and Captain Clark were in on the Missourii River capsized in dangerous whitewater, and Sacagawea (with her Jean Baptiste on her back), rescued Captain Clark's journals from the water, saving much of Clark's documentation of the first year of the expedition. It was these types of actions that earned Sacagawea immense respect from Lewis and Clark. On August 14, 1806 the Corps of Discovery returned to the Hidatsa-Mandan villages, having successfully made it to the Pacific Ocean and back. While Charbonneau was paid $500.33 and given 320 acres of land for his services, Sacagawea was paid nothing. However, Lewis and Clark were deeply indebted to her, and in fact, six years later Clark legally adopted both Jean Baptiste and Sacagawea's second child, and girl named Lisette born in 1812. Sacagawea died at the young age of 25 on December 22, 1812 at Fort Manuel, a Missouri Fur Company trading post in present-day South Dakota. She had suffered much of her life from some sort of ailment, which in fact nearly took her life once during the expedition. Sacagawea's contributions as guide, interpreter, and peacemaker were monumental.

pbs.org -  katecampbellstevenson.com/sacagawea.htm

Sacajawea Gives Birth to Young Explorer Pompey
On February 11, 1805, Jean Baptiste Charbonneau was born. He was the son of the Lemhi Shoshone woman called Sacajawea and her husband Toussaint Charbonneau, at Fort Mandan in what is now North Dakota. “Pomp,” as Jean Baptiste was soon to be called, was just a newborn, an infant of two months, when he and his parents left Fort Mandan on perhaps the longest exploration in U.S. history, the Lewis and Clark expedition to the Pacific coast, through country largely unknown to the non-Native world. Pomp would be the country’s youngest explorer.
Captain Lewis was not only the leader of the expedition, but also served as the doctor. He was present at the birth of the baby and reported “her labour was tedious and the pain violent.” He was counseled by others to crush the rattles from a rattlesnake and mix that with water to help induce birth. Although skeptical, it seemed to work, as Sacajawea gave birth soon after.
Two months later, on April 7, 1805, the expedition left Fort Mandan with Sacajawea and Pomp traveling up the Missouri in a pirogue. The expedition would not end for another 17 months when they returned to St. Louis.
jack mcneel - indiancountrytodaymedianetwork.com - 2014  
 

What happened to Sacagawea's children ?

After her death, Toussaint Charbonneau signed over complete custody of his son Jean-Baptiste and his daughter Lisette over to William Clark. It is believed Lisette died in infancy, but Jean-Baptiste was educated by Clark in St. Louis and then, at age 18 was sent to Europe. He would learn to speak English, French, Spanish and German and joined in the California gold rush. In May 1866, while returning from California, Charbonneau died of pneumonia near Danner, Oregon at age 61.
http://wiki.answers.com
Jean Baptiste Charbonneau --    "Little Pomp"   "PoMPEY"  -   to William Clark -- was educated in St. Louis under Clark's supervision and later became a traveling companion to a German prince, who took him to Europe for five years, where he learned several languages. Baptiste returned to America and for awhile became a mountain (the explorer John C. Fremont mentions in his journals encountering him.) During the war with Mexico in 1846, Baptiste was hired by the Army to guide the Mormon Battalion from Fort Leavenworth,   Kansas, all the way to California, where he became a magistrate of San Luis Rey Mission in California after the conflict. In 1866, at age 61, he learned of gold discoveries in Montana and set off with a wagon train for the gold fields, but caught pneumonia along the way and died on May 16 in southeastern Oregon.

A historical marker near the town of Danner marks the spot. I'm unaware of any information about the  fate of Sacagawea's daughter, Lisette. More information about Baptiste (and Sacagawea and Toussaint Charbonneau) is available from a pamphlet published by the Fort Clatsop Historical Association, "A Charbonneau Family Portrait by Irving W. Anderson. (Fort Clatsop National Memorial -- 503-861-2471 --  sells it in their bookstore.) Anderson's pamphlet also examines the two competing theories about the time  and place of Sacagawea's death. He concludes (as do most historians) that it was December 20, 1812, at  Fort Manuel near today's Kenel, South Dakota; not many years later, at the age of 100, on the Wind River  Indian Reservation in Wyoming   ...

pbs.org

Sacagawea was born around 1790. She was the daughter of a Shoshone chief. At about the age of 10, she was kidnapped by the Hidatsas during a raid against the Shoshones. Her father was killed. She then lived hundreds of miles away in a Hidatsa village on the upper Missouri where she was either sold or gambled away to Charbonneau, a French-Canadian trapper. As was custom in the Indian villages, Charbonneau had multiple wives.   

l3-lewisandclark.com

Six years after the expedition, Sacagawea gave birth to a daughter, Lisette. On December 22, 1812, the Shoshone woman died at age 25 due to what later medical researchers believed was a serious illness she had suffered most of her adult life. Her condition may have been aggravated by Lisette’s birth.

At the time of her death, Sacagawea was with her husband at Fort Manuel, a Missouri Fur Company trading post in present-day South Dakota.

Eight months after her death, Clark legally adopted Sacagawea’s two children, Jean Baptiste and Lisette. Baptiste was educated by Clark in St. Louis, and then, at age 18, was sent to Europe with a German prince. It is not known whether Lisette survived past infancy.
geocities.com/impurplehawk/sacagawea.html

The court appoints William Clark Guardian to the infant children of Toussaint Charbonneau deceased, to wit, Toussaint Charbonneau a boy about the age of ten years old and Lisette Charbonneau a girl about one year old.

Orphans Court record .  St Louis -  August 11, 1813

lewisandclarktravel.com -  2008
"The last recorded document citing Sacagawea's existence appears in William Clark's original notes written between 1825-1826. He lists the names of each of the expedition members and their last known whereabouts. For Sacagawea he writes: "Se car ja we au- Dead"  - Jackson, 1962."
It is not believed that Lizette survived childhood, as there is no later record of her among Clark's papers
http://en.wikipedia.org/wiki/Sacagawea
Sacagawea was a Shoshone, growing up in the Rocky Mountains. A Hidatsa war party captured her when she about 12 years old. She was traded as a slave to Toussaint Charbonneau, a French-Canadian fur trader who treated her and another native American woman as his wives. Lewis and Clarke and the Corps of Discovery in November 1804, arrived at the Hidatsa-Mandan villages and built a fort nearby. Sacagawea on February 11, 1805, gave birth to her son Jean-Baptiste Charbonneau. She was only about 16 years old. Charbonneau with Sacagawea was hired as an interpreter. Sacagawea, with the infant Jean Baptiste, was the only woman to accompany the 33 members of the permanent party to the Pacific Ocean and back. She proved to be invaluable to the expedition, and not just as an interpreter. She helped identify edible roots and berries, deal with overturned boats, bargan for horses, guide them, and much more.

Despite the fact that she had just given birh and had an infant son, she kept up with the men on their arduous journey. Her husband was paid, but not Sacagawea. After the expedition she gave birth to a daughter, Lisette. Sacagawea died on December 22, 1812, when she was about 25 years old.  

histclo.com

After her death, Toussaint Charbonneau signed over complete custody of his son Jean-Baptiste and his daughter Lisette over to William Clark. It is believed Lisette died in infancy but Jean-Baptiste was educated by Clark in St. Louis and then, at age 18 was sent to Europe. He would learn to speak English, French, Spanish and German and joined in the California gold rush. In May 1866, while returning from California, Charbonneau died of pneumonia near Danner, Oregon at age 61.
wiki.answer.com 

pbs.org

...
Sacajawea died at Fort Manuel South Dakota on December 20, 1812  soon after givingbirth to a daughter called Lisette

although there is an alternate theory that she lived to be avery old woman, living on the Wind River Indian Reservation, Wyoming.

After Sacagawea’s death, William Clark adopted her two children, Jean Baptiste and Lisette.

museumofidaho.org

http://inquiryunlimited.org/bk/sbks/ar/lewisclkar.htm