Burwell sisters

I have been learning more and more about my Price family over the past six years. After slowly adding sibling after sibling to my great- great- grandfather, Thomas Rees Price, I have also learned about their descendants as well. Last year I met a second cousin of my grandfather's (from the Abraham Price family) and I saw a paper she had with information that did not seem like it went with our mutual family. So I investigated the names and found that this was another sibling of Thomas. Here I was believing that I had found all the living ones and I learn about another one, who also lived in the Knoxville area where Thomas and other siblings lived. This was his sister Mary Price Burwell. She had married William G. Burwell in the early to mid 1860's. They had five children: Elizabeth (1864-?), Ann(ie) B. (1868-?), Mary Harris (1871-1949), William (1874-1895), and John S. (1878-?). Mary Harris Burwell married Clay Brown Atkins in 1894 in Knox County, TN. Well, after I have been going through some old pictures I came across this picture and was shocked to see the name on the back - Mary Burwell (Mrs. C.B. Atkins) and sister! Now I knew who they were! I know I had no idea who they were before and my father probably did not either, but now I can tell you who they are. So this picture is of Mary Burwell and one of her two sisters, Elizabeth or Ann(ie). I would like to know which is Mary and also which sister it is.