That's awesome Pemberley! I wish I had thought of something similar a few months ago when my DD turned 11!
She had told me (many months before her birthday) that she was hoping for a real-life owl with a real invitation to Hogwarts on her birthday - as in she believed it was all true and she'd get to _really_ go to wizard school. This is my kid who stopped believing in Santa and the tooth fairy ages ago (like around age 6) - but somehow was believing in a fictional place.
Of course I figured she'd grow out of it, and she didn't mention it again. Then her 11th birthday came - we had a nice party for her friends and family - no Harry Potter anything - she chose a different theme. But at the end of the day she was in tears - wouldn't tell me why, just kept saying she wished she could have her birthday over again. I'm sure now it was disappointment in not getting her owl letter - wish I'd taken it more seriously. :-(
Oh well - she's fine now with it (I think).
