It's kind of subjective. I might want something your mum already has. However, having said that.... the best quilting-related item I ever got was a gift certificate for quite a large amount to my favorite LQS. It was the gift that kept on giving, I literally used it all year long (well, okay, it lasted until August).
Another thing I do is make an Amazon Wish List with books, notions, etc. Anyone can view what's on my list. Maybe your mum has started one.
