I agree. If the school has no regulations against, and if it's not illegal, then we should not be acting.
Are there trans criminals? For sure. There's not a single cohort of humanity that is entirely devoid of arseholes. But what too many are crying here is the same pre-criminalisation that cis people throw at all trans people, all the time.
I'm not a criminal or a predator. And while I might disagree with Kayla's gender expression we have no business called her a child molester without better cause.