My daughter received a suspension for no reason other than a student said it was her. Now the girls that accused her say she didn't send it..help?

Simply put two girls sent a text to another girl involved in an ongoing investigation. The girls said it was my daughter, the principal believed them,suspended her and one other girl, without showing me proof that it had it happened...Said there were statements against her from two girls but we were never shown them and now they're saying we can't see them...She got suspended for four days, with Zero proof other than she said, they said....