1) You can find her on the 1900 census in Brinkley, Monroe Co., Arkansas, with Jeremiah Neely. This census gives birth month / year.... hers is listed as April 1872. There is also a Sylvia Powell in the household listed as the mother-in-law of Mr Neely but we cannot tell if that's his mother-in-law from a prior marriage, Sarah's mother, or if Powell was Sarah's maiden name / Sylvia's name from a marriage after she had Sarah. This census also asks about children.... Sarah has had no children; Syvia's entries state that she had only one child and that child was still living in 1900...so that'd be Sarah only IF Sylvia is Sarah's mom.
(you can find both of these record on familysearch)
2) You can find her marriage to Jerry Neely on 26 Oct 1898, also in Monroe Co., Arkansas. She marries as Sally (nickname for Sarah) Walker..BUT she is noted as being MRS. Sally Walker ...so seems like at least one more prior marriage.