North Arlington (or South Arlington) would be a quick hop into Georgetown, and if you stay here long-term, the arlington schools do a good job with special needs programming.
Lots of theater around here in DC and the surrounding jurisdictions. Plenty of good kids' theater - google Imagination Stage, Adventure Theatre, Puppet Company Playhouse, Encore Stage & Studio. Also "Theater in the Woods" in McLean.

(And Jammin' Java and Boogie Babes for musical offerings suitable for younger kids.)
MONA has lots of events too. (Moms of North Arlington.)