This might be of some help to you, i lived in the area and i know from 1901 census that there was a Sarah Kee still alive living at Lisnastrane Coalisland, not far from Stewartstown. She seems to be the mother of Thomas Kee and lived in his house. She is recorded age 82. I'm presuming that her and William were married? It is very difficult to get information on the period you ask about as all the census data of Ireland pre 1900 was lost. please let me know if you have more information on William and Sarah as i have an interest in finding out more about this Family.