Draw a bath for mom, and fill it with bubbles or throw in some bath salt. Pick a book or magazine for her, and leave it beside the bath with a towel for her to wipe her hands on. I recommend checking out Oprah's book club or our list of recommended life-changing books for suggestions! Or, set out an old favorite of hers if you know she likes to reread novels.
You can also set up your iPod and speakers (if you have them) in the bathroom and play relaxing music or an audio book for her bath.