Nancy Sevier was the tenth and final child of John “Nolichucky Jack” Sevier (1745 – 1815) and Sarah Hawkins Sevier (1746 – 1780). Nancy was born in early 1780 on the family plantation on Little Limestone Creek, six miles south of Jonesborough in Washington County, Tennessee. An Indian uprising that occurred at that time made it necessary for the family to go to Fort Nolichucky, which was a very difficult six miles from their plantation. Sarah, having complications from the birth, made it to the Fort, but one very early morning, she passed away. She was buried that same evening in the nearby forest amid a thunderstorm. John Sevier married again to Katherine Sherrill (1754 – 1836) on August 14, 1780, and she raised Nancy.

According to Notable Southern Families (Vol 4), Nancy married Walter King (1764 – 1830) on February 19, 1795, when Nancy was 15 years old. The wedding is described in John Sevier’s published Journal and the couple is mentioned often in that Journal. Walter and Nancy had eleven children during their marriage. It is noted that several online genealogy sources state that Nancy had an earlier marriage to Benjamin Brown; Nancy would have been ten years old on the date specified for this marriage. More recent research has shown that marriage never took place; Benjamin Brown was actually married to Sarah Hawkins Sevier, Nancy’s older sister.

Nancy Sevier King died in 1825 and according to Miss Hattie May's letter (a King descendent) dated Kingston, July 3, 1889: "…Nancy King and her husband are buried in the Kingston burying ground.” Based on this letter, the Bethel Historical Cemetery is listed below as the burial site for Nancy (this cemetery was formerly known as the Kingston Historical Burial Ground). However, no grave for her has been found to date.