I agree that she will need to reconsider her medium and paintable surface. She just needs to expand her thought process about painting. You can help her do this by showing her sites like this google images search page.
https://www.google.com/search?hl=en&...08.a6SxjGajqgQ
She's going to fall in love with this!
Also put her in touch with some books about painted quilts -- American Quilting Society can help.
Jan in VA