Muffy wanted to make sure we mentioned all the places to buy stuff in the area. We'll try to get through this as quickly and painlessly as possible. Here goes:
The hospital has a pharmacy and a great gift shop. Outside the hospital, there's a food court called the Galleria and more stores.
If you get the chance to go a little farther, the town next door (Brookline) has some terrific shops, and it's a great place to take a walk with your family. You're also not too far from downtown Boston, and there's just a TON of great shopping there (apparently).