J. T. Shine who purchased the cemetery lot must be buried nearby, as his second wife, Leeana S. Abernathy Shine married C. A. Gill in 1894. Do you happen to know when it was purchased? That would help narrow the time frame in which he died.
Lillie's middle name was Pearl. She married John C. Black in Hill Co., TX, in 1795. I found them in Ellis Co. census in 1900. Also living with them was an 11 year old boy named Jessee Shine, who is identified in the census as John Black's brother-in-law, so John T. Shine was alive as late as 1888, but dead by 1894 when his widow (and the mother of Lillie Pearl and Jessee) married C. A. Gill. Since Jessee is living with his sister in 1900, it's possible that their mother died between 1895 and 1900 and was buried in that plot in Hill County, possibly with her first husband.
As for the other Shines buried there, Mrs. M. J. Shine was Martha (Mattie) J. Abernathy Shine, daughter-in-law of John T. Shine. She married J. T.'s son Hillary T. Shine in Grimes Co., TX., in 1876. They were living in Hill Co., in 1900. George was probably another son of John T. and Leeana. In the 1880 census for Bell Co., John and Leeana had a 3 year old son whose name is very difficult to read on the microfilm at our library. In 1900 George H. Shine was living in Hill Co., TX., and gave his dob as 1877, which would fit with the 3 year old in 1880.
Do you know how to go about obtaining estate records in Hill County? With minor children left behind there are surely some records left behind concerning John T. Shine and Leeana Shine Gill that might shed some light on all these people's relationships.