So I have to pay (with higher fares) for a youngster to be entitled to enter CCR without a First ticket? Respectfully, I would support another solution more. The rules applied to me as well when I was under 18, so she is not being singles out. (As far as the wording in her tweet it shows she needs some strong discipline, and if a caning is too much then being denied access to an adults only lounge is a start.)

Could this be solved by a signed written statement in which she promises not to drink alcohol in the lounge and in which the parent gives consent to her entering the lounge under those circumstances?

That being said, she clearly has an attitude problem.