We've been to VA beach in March, and stayed at a hotel with an indoor pool overlooking the beach. Very nice. The Boardwalk there is great for scooters and bike riding. There's a nice playground right on the beach as well. We got lucky and had a day or two that was warm enough to play on the beach. DS did not seem to mind the 50 degree water temp, but I sure did!
There's an aquarium in VA Beach, and other kid-friendly tourist attractions if it's not warm enough to be out on the beach. Nice perk of VA beach is that it's a real city, and there are plenty of things open in the wintertime. Not so much with OBX.
mommy to DS who is 9
DD who is 6
and my girl in heaven