LOL!
I agree. My DGD, at ten, would have preferred to chew glass and die before dressing in any Princess getup and getting her hair done. I know that she is unique, but before scheduling this activity, I would show the child a video. 10 YO girls are pretty self-conscious, so I would think about that aspect.
My DGD has been a pin trader for years, and she loves this, but I would also look at Epcot, the "impossible" missions. I forget the name they go by now, but Kady did them when they were Kim P and that last one, ( what the heck is it called???) and the whole family had a ball!
I would schedule a few character meals, beginning with Chef Mickey on arrival day. No matter how a kid feels about character meet and greets, this is a really fun way to kick start the trip. We would use the monorail as am "introduction" to our trip, so maybe an overview, including the Epcot loop, and a visit to CM would be a nice way to see how she is going to feel about WDW.
I think that the meal at 1900 PF with Cinderella and the Steps is fun too. You do not have to be a Disney Geek to enjoy the sisters and Lady Tremaine.
DHS is a fun place for tweens as well. There are attractions that while Disney related, are not all characters all the time. The Muppet show, and the Great Movie ride, Tower of Terror and Fantasmic all made my DGD laugh. She had seen the Beauty and the Beast show many times by that age, so we skipped it the last few trips, but I bet a 10 YO would love it for the first time, and there is no need to be familiar with the movie It is a play, and pretty well done.
One of the biggest misconceptions about WDW is that you need to know all about Disney in order to enjoy the experience. I do not agree. If you can, watch the movies, and see how she feels, but no matter what, she will have a great time.