What a horrible and judgmental thing to say! I believe she is asking a very valid question that many teen-aged girls probably have. Now, I would agree that the proper place for the question might be in the Ask the Apologist section where it will not receive any subsequent comments, but still, to tell someone to stay away from here is irresponsible and uncaring, and unchristian as well. If someone is seeking the Truth, why in the world you ever push them away, just because YOU are uncomfortable with the subject matter?
And to the OP, yes, of course it’s wrong. But the reason it is wrong for girls is because any sexual act should only be between a husband and his wife. The reason masturbation specifically is wrong, is because when a husband and wife are together making love, masturbation alone is a very selfish act, and it removes the unitive (bringing the couple together) aspect of love making, and can ultimately separate the couple emotionally.
And I also agree with another comment, you may need to reconsider going to your friends for advice on such subjects in the future.
~Liza