What do you think about this prank?

Our little sister loves Donny Osmond...she is obsessed with him, she talks about him 24/7. So me and my friends decided to write her a letter pretending its from him, and mail it to our house. In the letter we're going to say "Chelsea, a little bird informed me of how much you love me. Well all I have to say to that is, stfu and get a life! I have no interest in little teenage girls." And a bunch of other stuff that'll be sure to put an end to her infatuation with this old geezer.