They don't. My 7 year old went to both parks this Summer, and had a great time on plenty of slides. There was PLENTY for her to get to do, and we didn't even get through everything.
Maybe it is just hard to tell from the website! They only show the areas geared toward younger children as under 48 inches, and then they show the big slides/ and the steep wilder rides. But if there are gentler slides that a 48 inch tall girl can go on, then it might be worth it. I just don't want to go and have her be the only one that can't do anything fun. She tried the big slide at SSR pool last month and plunged under the water, and another slider sort of ran into her...so now she's terrified of the bigger slides.