To tell my daughter she has a terrible singing voice

[fudgefeet]

My daughter (9) came out of school yesterday telling me that they had been learning a new song at school and she realised she is "amazing" at singing it. She then gave me a 3 minute car ride home of what I can only call deep guttural warbling that was supposed to be Mama Mia. She has never had much of an ear for music and struggled to sing nursery rhymes in tune but now she has added what she calls her own style to the mix it really is quite shocking. I did my best to keep a straight face the whole way through as she sung her little heart out.
She is a very loud child and often likes to tell people how brilliant she is at things even when she's not so I don't want to tell her it was great as she will no doubt start sharing her new talent with everyone and probably even ask to sing in assembly. Should I just let her carry on in blissful ignorance or find a way to tell her its awful.

[Daviz999]

I hope she grows up and learn to sing well!
May be someone is interested how to learn sing better? tinyurl.com/zdtwtw2