I was just looking in the success threads for Demi and I see one for Nov. 28th. Not that long ago.
Where did you mail your request? Was it here?
Demi Lovato
CESD Talent Agency
10635 Santa Monica Blvd.
Suite 130/135
Los Angeles, CA 90025
Here is the success post for that addy, with a personalized photo:
http://www.fanmail.biz/mboard/viewtopic.php?t=114745
There was a more recent one in Dec. but that was from a venue, and is not longer available.
Here is the page listing all the previous successes. Do have a look at them, where they sent, the dates they sent, and how long they took to get them back.
http://www.fanmail.biz/feedback/Demi_Lovato.html
The other thing to do is wait 5-6 months and if you still haven't heard back then try again. But you need to check the success posts to see how long she normally takes to reply. Some celebs can take up to ten months. In a case like that you need to wait longer.
I do hope that helps. {thumb2}