I think 12 and 1/2 is still young enough to want to be a princess for a day.
I would take her.
If you decide that it is not a good idea, then
you could always take her to the Grand Floridian to get her hair done.
My nieces went there. They wove their hair in such a way that it framed their faces like a crown. They looked beautiful. The plus was that they were told when they took it out, their hair would be all curls and it was.
They were so pampered. The person that took care of them was wonderful. I'm sorry that I don't remember her name. They got lots of pixie dust that day.