To contact Christy, these are the  addresses I have found.  The only problem is that supposedly they never get to her and nothing is ever done with them.  She never receives the mail and never responds.  I have tried to write her and never got anything back for all of these addresses.  I think that you should still go ahead and give it a try but, don't say I didn't warn you.  I have contacted some affiliates asking about any alternate addresses, and they have told me that none of the others are valid. 
CHRISTY ROMANO
c/o Even Stevens (or Kim Possible)
Disney Channel
3800 West Alameda Ave.
Burbank, California 91505
USA
CHRISTY ROMANO
c/o The L.A. Studios
3453 Cahuenga West
Hollywood, CA 90068
USA
CHRISTY ROMANO
9150 Wilshire Blvd. #35
Beverly Hills, CA 90212
USA
No information on Christy having a public email address or screen name.
To contact me, for questions, suggestions, facts, or information that you can give me relating to Christy, email me at:
idolizingchristy@yahoo.com