It's easiest to work around the system and create a new account, you may well have to conceal evidence of the old identity with:
A different internet connection IP address, if a DSL connection it could be a matter of turning a modem on and off, in other cases your unique address may be fixed,
Sign up through a different email address, like a free Gmail account.
Clear browser cookies associated with the site, o clear all cookies.
They own the website and can do as they wish but write them a complaint and they will unban it. Make sure you mention your child's disability so that they understand the reason for her actions.
Goodluck
KW
PSYDUCK!
They sure can do it.