Maybe Berkeley Springs? It's a spa town, has cute little shops, some nice restaurants and is a short, easy drive.
If a little more corporate what you have in mind the Hyatt resort in Cambridge on the Eastern shore is comfy, nice indoor pool, rooms with pretty bay views and is a short drive to Easton, which has some really nice restaurants and cute shops as well as close to the Blackwater wild bird refuge, which is an easy walk/drive tour and very pretty. Or, the Tidwater Inn in Easton's really nice and sort of combines historic charm with larger hotel amenities.
Down in southern MD, I"ve always wanted to try this place - once you're over there you could have a gentle walk around Historic St Mary's City and the college, both of which are really pretty. I'm not as sure about dining options, though surely one can get good seafood somewhere!
http://www.woodlawn-farm.com/