I agree with the suggestions about the gift cards and thank you notes. Maybe bring a special cupcake(s) for her...anything to show appreciation.

Sometimes, cash money can feel cold. If she doesn't want it, you can't force her to take it. I personally dislike arguing to give someone money, trying to insist, when they equally insist not to accept. I don't like arguing!

I hope all works out well, she sounds like a nice person.