It may be a one-of-a-kind quilt then, made without a pattern. She may have made up her own applique blocks from scratch, or by outlining photos.
It may also have been made from a panel print. I found a couple of those type of panels while Googling, but they were just four pictures.
If the quilt was displayed in a guild show, you may be able to find a photo of it online in the guild's gallery of pictures (assuming the guild has a website; not all do).