I appreciate your reply very much, and it's interesting that the cemetery is on your property. I can help you decipher the inscriptions, I think. The stones were legible when I saw them, and I took photos of them.
You're right that the stone with one name on it reads S.K. Green. This stone is for the grave of my ancestor Samuel Kerr Green, who died in March 1860 in what was then Grimes Co., Texas. Since Samuel is buried on land that had belonged to his brother Benjamin and is buried with Benjamin and Benjamin's family, it seems clear to me he died at the home of his brother Benjamin and was buried in what became the family's cemetery.
The other stone has the surname Green and the initials B.S., M.M. Green, S.B., T.E., J.W., and L.C. B.S. is Benjamin S. Green, who was a brother of Samuel Kerr Green. They are children of John Green and Jane Kerr of Abbeville and Pendleton Dist., SC, and Bibb Co., AL.
Samuel was born abt. 1790 and Benjamin abt. 1795, both in Pendleton Dist., SC. Benjamin died in March 1860 in Grimes Co., as did his brother Samuel (in a section of Grimes that later became Waller).
Benjamin was married twice, and M.M. is his second wife, but I have yet to find her given name. The children buried with Benjamin and M.M. are all by his first wife, and are Benjamin S., Jr., J.W., Thomas L.E., and Lucinda C. (Caroline was her middle name, I think). Tax and deed records in Waller Co. suggest that none of the four children married, and that they lived together farming their lands up to the ends of their lives, with Lucinda moving to Harris Co. at the very end of her life.