It would be nice to repay her in a way for her generosity. Certainly, a small lapquilt or wall hanging, placemats or a bag would be lovely. If you do not want to make something, or think she might be embarrassed, perhaps each time you use some of her fabric, you make a charitable donation to a charity of HER choice....well, not everytime, just every so often. I'm sure she would just love to see the smile on your face in any case. Most quilters get such joy out of someone loving what they love. Be sure to pass on her generosity as she did to you.
Ahhhhhhhhhhhhh....lovely.