My DD turned 11 while we were there also, and they put her name on the TV (resort channel) and delivered ballons with a card signed by Minnie (Mickey must have been out fishing!). She thought it was pretty cool. Just let the front desk know.
We asked her if there was something she wanted to do like kayak, horseback ride, etc and she said she wanted to go Juliette Low's house (Girl Scout founder) in Savannah and then to the beach and pool, so that's what we did.
I feel bad for my youngest DD. This year, we spent oldest DD's birthday at HH, will spend DH's at WDW next month, and mine at WDW over New Year's. Poor Katie just gets her regular birthday party at home. I'll have to come up with something really special for her.