I don't know what days you plan to be at USF/IOA, but if they are weekdays, I wouldn't worry too much about long lines. I've poppd in there on a couple of recent Wed. afternoons and there weren't any lines at all, not even for Spiderman. That said, if you're going on a weekend, you might have more of an issue. I would say your best bet, either way is to get there when the park opens, and do any dining at off peak times. (like 11am or 3 for lunch) when most others are dining.
They normally offer Express passes, which are free for everyone, but I think they are discontinued currently...but the reason for that, I believe, is that there isn't much of a need for them right now.
If you're travelling with another adult, and need to take turns on rides the little ones can't (or won't) go on, I'm pretty sure they offer a baby swap, so that you could each ride without waiting twice. There is also a single riders line for some attractions (MIB is our favorite!) and if everyone isn't doing that attraction, can be a way to move along quicker.
My kids are 7 and 9 and we use the single rider lines all the time...but they're not "little" (according to them anyway!)
Good luck!
Karen