Hi Amy!
The Pirates League is awesome and your son is going to love it!
I loved watching my boys while they were transformed into pirates and your daughter may enjoy watching her brother. This experience is more than just sitting in a chair while they apply make up, it involves a few steps. She is more than welcome to join her brother and watch him along the way.
If she isn't interested in watching her brother, here are a few other ideas for your daughter while she waits for him:
There is a place just outside the gift shop of Pirates of the Caribbean that does hair wraps.
She can shop in the gift shop at the exit of the Pirates of the Caribbean. In addition to pirate themed souvenEARs, they have some fun jewelry she may enjoy.
She could visit the Sunshine Tree Terrace for soft-serve ice cream (its near the Enchanted Tiki Room not far from The Pirates League).
She could start playing
A Pirate's Adventure - Treasures of the Seven Seas. The starting point is at The Crow's Nest which is located as you're heading out of Adventureland towards Frontierland. She could pick up the map for everyone so that you could all begin once your son has finished his pirate transformation.
These are things that are close to the Pirates League. If you're comfortable with her venturing a little further away, there are more shops near the Magic Carpets of Aladdin. She could also visit Aloha Isle for a famous Dole Whip.
Please feel free to visit with any other questions. Its a pleasure to assist you!
Wishing you minnie magical memories :-) Allison V.