Go to the Hospital Director.

I can't search for anything specific without knowing what State you are in, as each state has slightly different guidelines.

Who signed the child into the hospital?
Did you sign any paperwork? If so, reread it to see if your and the patient's rights are listed. There should be a sign or poster or such readily available for patients to read about their "inpatient rights." Those are intended for those over 18, however, YOU do have those rights for your child (assuming you have legal custody of the teen.) Being hospitalized--in even in a psychiatric unit--does not remove any of your (or the patient's) rights. You also need to verify that her father did not sign the okay.

You can do an internet search for your state by asking the question, "Can a hospital psychiatrist medicate my child without my permission in the State of ____ " tweak the question to get the links that suit your needed answer.

But tell the hospital Director/Administrator immediately of your request.