Most genealogies show she was born in Nashville, Tennessee on November 3, 1776 (although one shows she was born on Nov. 3, 1784 in Laurens Co., South Carolina and yet another shows November 13, 1776 in North Charleston, South Carolina). All agree that her father was Roger Brown (b. abt 1750 in Ireland). Most show her mother as "Molly" b. 1753 in North Cortner, Bedford, Tennessee (One shows Molly born abt. 1754 in Ireland and yet another shows her mother's name to be "Jeaney" b. abt. 1750).

Rebecca was married to Thomas Adair whose birthdate was 25 Oct 1771. No marriage date but various locations are listed: Charleston, Souiance, and North Charleston. Also, many descendants include "Jefferson" as a middle name for Thomas. However, research in available records with his name and in his time period ~ no middle name is included ~ he is always Thomas Adair.

They had the following eleven children: Margaret Adair, Fairby (Ferreba?)(Phoebe?) Adair, Eliza Jane Adair, Samuel Jefferson Adair, Sophia Adair, Sarah Ada Adair, Thomas Jefferson Adair, George Washington Adair, John Wesley Adair, Mary Ann Adair, and Laney Ann Adair.

After joining the Mormon church in Mississippi, Sarah with other members meaning her living married children and their families traveled to Nauvoo, Illinois but her husband Thomas stayed behind. They arrived in Nauvoo just days before "the exodus from Nauvoo" began. Thus, the journey just completed was for them an unexpected extension of travel 'to begin anew ~ their journey to pursue' to be with the 'Saints'. Their destination this time: settlement in the Valley of the Great Salt Lake to be among and with the 'Saints'. Each day brought definite overnight stops and then of necessity along the way a more prolonged one for them and others ~ Mount Pisgah, Iowa was their first prolonged stay.

Rebecca died in Mount Pisgah and two grandchildren along with many others following "the terrible sickness" that "came upon the saints." Her name is listed on a monument, which was erected there in 1888 and also the names of her very young grandchildren.