Christmas present for boyfriend's mom?

My boyfriend's mother and I are pretty close, and she's coming to see me this weekend at my university. I want to get her something for Christmas because she has done so much for me and is so supportive of my relationship with her son (she is even taking me to his basic training graduation next month because my own parents wouldn't pay or approve of me going to California alone). She's driving two hours to come see me this weekend when she could be spending that time with her other sons, and I know she's bringing presents that she and my boyfriend bought for me so I want to get her something nice. But I can't think of anything that would make a good gift from an 18-year-old to her boyfriend's mom. Any ideas?