If you put THIS IS NOT PREJUDICE can you still be sued?

It sounds to me like you made a group against a pageant and wrote terrible things about the pageant, and now they are suing you for slander. Writing that won't stop anything, you falsely accused an organization and are out there spreading lies about them... have fun in court there's no way you will win. If you never even once used their name or gave the umption that it was their pageant then no they can't do anything.