My 4 year old has been on pretty much everything but Space Mountain. He's loved everything except Rockin' Rollercoaster. He is a big 4 though. He just hit the 48" mark on this trip. As in when we went to ride Primeval Whirl at AK one morning the CM tried passing a credit card like thing between his head and the bar and said "boy he's RIGHT there exactly at it!" and let him on. Later in the day we went back and I could run my finger between his head and the bar (your spine compresses throughout the day and you are a teensy bit shorter at night than in the morning).
He's been on every ride at AK and loves every single one including Everest and Dinosaur.
He's been on everything at Epcot as well. The exception is that we only let the kids do the tamer version of Mission Space, not the more intense one.
MGM he's been on everything too. Tower of Terror was one that he enjoyed while he was on it and said he liked it for about an hour after then he started saying "maybe I will skip that one next time" the more he thought about it. He rode Rockin' Rolercoaster and didn't get upset about it but said "that was not my favorite."

His older brother wanted to ride again (we had a baby swap pass so Dad was going to take them) and my 4 year old passed on the 2nd ride. He didn't like the fast take off. Was fine with the "during" part, just didn't like the blast off.
At MK he's been on everything but Space Mountain. He usually wants us to hold his hand or put an arm around him so we've waited on that one since we couldn't sit next to him.
Our rule is that no one has to ride anything they don't want to and Mom and Dad are OK with using the chicken exit with them if they change their mind in line. We encourage trying a "big boy ride" but we don't push and we definitely don't force. Each kid is different. While my 4 year old is a HUGE thrill seeker and daredevil, his 6 year old brother is not and our trip in February was the first trip for him to ride anything even close to a thrill ride. He didn't like anything even slightly fast for a very long time. He left this trip saying Everest and RnR were his new favorites. He hasn't been on Space Mtn. for the same reason and he doesn't want to do ToT because it looks too scary.
Start your DD off slow, try Goofy's Barnstormer before any big thrill rides and see how she does. If she meets the 40" height requirement for things like Splash Mountain and Thunder Mountain and she is interested in riding them, she will more than likely do just fine.