I say thank you. It's not a big deal but I do get annoyed when people gush over her, want to touch her, play with her hair, say she should be a model etc. She's not a doll (and she's only six).
I would much rather they asked her about school, what books she's reading, future careers. I don't want her to think that appearance is what matters most in this world. It's not the message we send her at home but the outside world seems to think otherwise.