It really depends upon what she already has and what your price range is. Does she have a really good pair of sewing shears and/or pinking shears? What about a large cutting board and rotary cutter? She may like a new sweatshirt/T-shirt, with a sewing/quilting-oriented design on it. If she does a lot of hand sewing, a large sewing basket might please her. Into the sewing basket, add a new seam ripper, small sewing ruler, maybe a pair of small scissors, etc.
If she quilts a lot and doesn't already have one, a June Tailor Shape Cut Ruler would be wonderful.
http://www.amazon.com/June-Tailor-Sh...hape+cut+ruler