The 48" rides include RnR, Alien Encounter and Primeval Whirl. I would assume that when Mission Space opens it will also be a 48" ride.
Most everything else is 44" (Space Mountain) or under, so she really won't be missing much if she isn't allowed on. The important part is to prepare your DD for the fact that she may not be able to ride this year... but she will always have something new to look forward to next time.
I know my DD was barely over 48" when she 1st rode RnR, and she had on tennis shoes that were had a slight lift, probably no more than 1/8 inches--- they were just the ones she wears everyday. They must have measured the poor child 3 different times for both RnR and Primeval Whirl every time we went on it (and we held our breath everytime)... but I had well prepared her for the fact that she might not be able to go on it, so when she was allowed, it was that much more special.
As Jimmybop said, the height restrictions are put there for a reason, and with people getting as sue happy as they are with theme parks and carnivals, it isn't any wonder that they are super strict with the measurements. I am glad that they think enough of our safety to be diligent.
Good luck to you, and I hope that your DD isn't disappointed.