If you are seeking a document with her name and James Allison York together, good luck! Perhaps your best hope lies in his probate, if there was one? There is a "lot" of inference 'cause the two youngest kids in 1860 were enumerated as "Buddie" and "Babe". I'm suggesting the nine-year old Martha would morph into Ida May. James A. York and Ellison York were the same person, circumstantially. Both names listed as slave owners 1850 and 1860 Lavaca County. You may need to spend hours in Lavaca County Courthouse?