Mel, did you see
this thread? It's in Plano but the indoor school house photos that were posted show some nice possibilities. That'd be cute. Plus it has outdoor stuff if it's not raining. Shouldn't be much walking.
I know of some hotels, but I don't think it'd be terribly fun for a family and nothing specifically in Carrollton - I rarely shoot in that area!
Oh - my other idea would be finding a colorful ice cream or frozen yogurt shop. I shot in a pacugio (sp?) once for a pair of sisters and I thought it was cute, especially if you want to do some lifestyle stuff.