I believe your ancestor is Thomas Jefferson-6 Reavis b 1849 Winston Co AL, s/o Jackson James(or vice versa) and Mary Elizabeth Williams. The Luina S. Morphew listed as Thomas' wife on the 1900 Census may or may not be his only wife. I have seven children from a different time period that may be a different mother, inluding Martha Jane. I would suggest checking the archived messages of the Reavis List at rootsweb and if the information you need is not there, then post to the List because there are private databases maintained by some of the researchers.
Do you have death dates for Thomas and Luina? I have that they both died at Pine Valley, Muse OK.