Let me clarify that the 3 Express Pass Hotels (Royal Pacific, Hard Rock, and Portofino Bay) offer both the Unlimited Express passes and the 1-hr early entrance. The 2 newer hotels ONLY offer the 1-hr early entrance.

While I would say in general, the Universal parks are geared a bit more to an older (i.e. teens and up) crowd as compared to the Disney parks, there are definitely rides in both Universal parks focused on the younger ones.

You can check out the following links to see what rides/shows each park has:

Islands of Adventure
Universal Studios-Florida

The play areas in both parks are geared more for younger children and would probably be enjoyable for your daughter. And be careful of some of the shows. The Poseidon's Fury show/ride and the Horror Make-up show might be a bit scary for a 6 yr old.

And one final point, don't waste your time waiting an hour for the Pteranodon Flyers ride. It is an OK ride at best, but not close to worth waiting an hour just for a less than 60 second ride (it doesn't have an Express Pass entrance so everyone has to wait in the regular line.) And depending on the time of the year, if it is warm enough, my kids love getting wet with the Bluto's Barge and the Dudley Ripsaw Falls rides. We will wear swimwear and flip-flops to the park and bring an extra shirt. We'll head over to those rides (get a locker and put in anything you don't want to get wet.) Then using our Express Passes, we'll hit one, then the other, then back to the other, and do that until the kids are tired (usually a couple of hours.) You will be thoroughly wet by then. Change into your dry clothes. We will normally head back toward the rooms as the kids are tired (and the adults can be too.) We'll stop for lunch somewhere and then let them hit the hotel pools or just take a nap for a bit (while the adults shower and get cleaned up.) For my kids that is always one of the most looked forward to "traditions" we had for visiting Universal.