I like your idea of getting her a rotating cutting board. That would be a very useful gift. I am not familiar with the Omnigrid rotating board, but I can tell you that the one by Fiskars is terrible, ask me how I know!
Another idea, does she have applique scissors? They have a duckbill blade that really makes cutting appliques easy. If she has been doing applique for some time she may already have a pair.
A gift card is always a welcome gift too!