Lucinda, So sorry for the huge delay in responding, I don't come here much at all and was surprised by your posting. My neice, Yolanda Nix, daughter of my late sister, Norma, does indeed have a portrait of them. It is an oval antique frame with the convex glass.
In the portrait, my Grandfather, Jacob B. Vinton is sitting as was the style, and Carmelia is standing behind him with her hand on his shoulder. I am not certain of Yolanda's address, but she is on facebook and posts regularly. You could probably contact her through that. Velma probably has been in contact with her.
She has quite a few Vinton treasures, since I moved to Hawaii yrs. ago, I left the heirloom .30-.30 Rifle that was his and then my dads, and an old 12 gauge long shotgun made in New Braunfels Texas that was again his and then my dads.
The rest is much antique furniture that was my mom, Caroline, and my dad Jacobs furnishings over the yrs. Yolanda became caretaker of most all of our things.