Maybe get her a mug with a pic of her and your Dad from Kodak Gallery.com. My Mom is getting a personalized license plate for her car with the nickname my kids call her on it. MIL is getting a mug with a pic of DH and our two kids on it, a new cordless phone, a massager to put in her chair, and something else that I already forgot LOL!! THe cordless phone was the kids' idea, they want to leave her sweet messages when she's not home. THink out of the box, you're sure to come up with something.
Good luck!
Selena