Im so sorry, but if your husband's g-grandmother's name was Nancy Jane, then the Mattie that you're looking for is in all probability, not the same Mattie Self that appears in the picture.
The Mattie Self in picture is not related to Nancy Jane, she is the daughter of Joseph Watson Self and Josephine T. Hanes.Mattie is also the granddaughter of William Self and Sarah Taylor, and Joshua A.J. Hanes and Margaret Haden, and the sister of George, William (my grandfather), Thomas, and James Self.
Since it took my over 8-years to find which Self line my family descends from, I have a lot of information and will gladly look in my files to see if I have anything that might help you.
Please feel free to contact me directly ~ Judy Emisix@aol.com