How to tell your child they have Aspergers Syndrome??

Hi I have a 7 year old daughter diagnosed 2 years ago with Aspergers. I am feeling that the time is right to tell her about it as she doesn't know about it and has started to ask a few questions and seems to have an awareness about her brain 'not working properly as she has quoted a few times.

I am gathering as much information and advice as possible at the moment on how to tell her best. I don't want to word it wrong to her and I am very aware that what I say could affect her for the rest of her life. I want her to see it as a positive that she is very gifted and talented etc.

I am also trying to prep school up so that they have a good knowledge base in case she asks them any questions.

I would really appreciate some advice on how best to handle it, what to and what not to say etc??

Thank you - Kat