Hi, Ivana!
Congratulations on your upcoming voyage aboard the Disney Dream -- she is beautiful and magnificent as they say she is!
If you're thinking of the Bibbidi Bobbidi Boutique like the ones at Walt Disney World, there isn't a princess specialty salon on Disney Cruise Line. However, you can book your daughter for an appointment at the
Senses Salon once you are on board. I recently had my hair done there and found the prices very reasonable compared to my salon at home. I think an 11-year-old girl just may appreciate the grown-up salon more than the more whimsical ones anyway.
For celebrations on board, I suggest decorating your stateroom, ordering a special cake to be delivered at dinner and providing them with the choice of port adventures. My kids love the water, and we're planning on a splashtacular port experience for an upcoming birthday for our 11-year-old. Combined with that "surprise," I'm going to have a new underwater digital camera waiting for him in the stateroom the night before my birthday boy's adventure. Maybe you can create a theme to celebrate your daughter's birthday and your son's graduation. What a joyous voyage for your family!
I wish you nothing but the best as you prepare to commemorate such milestones for your family. Have a wonderful day and a magical vacation -- congratulations and happy birthday! Bon voyage!
Andi