S.M.
My kids love six flags, they are 7, 11, 12. We have had season passes for two years, since age 5 for my youngest. For my youngest he isn't crazy about roller coasters but his cousin of the same age loves them. The website gives height requirements for each coaster but there is still plenty to do for my youngest. My kids also love Hawaiian Falls water parks (opens memorial weekend), several in DFW area, FW Zoo, and the Science Museum in FW. The Aquarium in Dallas is fun, and there is a new children's museum in Dallas that I've heard is very good. Have a fun visit!