During the Till We Meet Again show in the lobby on the Magic, when there are all of the lines for pictures with the characters, you could also meet the actors and dancers. There was one group on each side of the atrium, and they had no line at all because everyone was busy with the characters. So we got a chance to to talk to them, take pictures with them and thank them for making our cruise magical. They're so sweet and very happy to be acknowledged.
As mentioned, throughout the cruise they are the character handlers, so you can also chat them up while in line or even if you notice them while walking by. The handler at the Frozen meet and greet was the dance captain (who was also our muster station captain) and he was the nicest guy! We asked him to be in the picture with us and the Frozen gang, he's now permanently part of our photo book

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Lastly, something sweet that happened to us, the actor who plays Peter Pan in The final show (I think Dream? Sorry...) came up to us at O'Gil's because he had noticed us giving them a standing ovation (we always sat fourth row center) and he wanted to thank us and tell us how touched they were. It was just so sweet!!
So your daughter definitely has many opportunities to talk to the entertainers. That was actually one of the best parts of the cruise for us.