T.K.
A Fancy sewing machine with bells and whitles she doesn't already have.
My MIL loves the kind of gift that is a service. Last year for Mothers Day, we redid her flower beds and she was thrilled.
You could go to her house and overhaul a room to make her a crafters paradise. You could do the craft room unveil at the party by having a picture of it blown up and wrapped.