I hope I can offer some help. Serafina "Fine" Cunningham, the wife of Martin Van Buren Garner, was my Mother's great aunt. Mama lived with their daughter, Cousin Laura Meggs, when she attended college. Fine was the daughter of Anderson Cunningham, who married Martin V's sister, Sylvana. I don't know the name of Fine's mother but you can probably find the given name at least in the Saline County Arkansas census. I'm sure I've seen it there. My great grandfather was Andrew Jackson Garner, Jr, younger brother of Martin V.
I have photos of her headstone that I would share taken by a cousin, in case you haven't seen it. Actually you can find it online at http://teafor2.com in Arlington Cemetery. I also have a photo that we think is Aunt Fine taken at the headstone of Martin V's mother, Eliza Garner.
If you are still needing information please contact me and let's see what we have to share. I have the address of another researcher that might be able to help you more than I can. Hope to hear from you. Marcia