N.C.
I have a 7 yr old son that we took along with my brother in law and his family of 5 (2 girls aged 9, and 13 and a boy 12)to South Padre Island this summer. It was absolutely gorgeous. It is about 6 hours away but it is definitely worth it! There is a Schlitterbahn that is great for families, and there is the beautiful beach. There are dolphin encounters, and fishing on the pier. you would definitely have a a great time with the whole family.