Actually, I respectfully decline to act as ad hoc surrogate police for any other party, especially anyone trying to lord it over children. I figure each party can negotiate with each other party without my generalizing advice ... except to say: (a) I don't think judges hold anyone under age to a binding contract, and (b) I don't think a judge inflicts a non-negotiated contract on anyone, and (c) I don't think any judge will uphold any contract without "consideration" between the parties, that is, money change hands.
Ask a lawyer who practices in your jurisdiction.
When was the last time your saw a school child get a trial before being given a detention?
I once asked a teacher why the United Nations Universal Declaration of Human Rights doesn't seem to apply to school children. His response: "Children don't count as human." (I should clarify, he *was* joking.)