The teacher alone would not have the authority to kick the girl out.
The administration should have been informed and the teacher put on probation by the administration.
From the article:
“But days later, the family received a call from an administrator urging them to withdraw their child from the school. When they refused to do that, he said the school would kick her out anyway:
“(He said) ‘I think you guys should do a parental withdrawal for the child.’ I said, ‘I can’t. I can’t do that. We refuse to withdraw her,’” Misty Dunham said. “He said, ‘OK thank you for saying that,’ and continued on saying that, ‘Well, we’re going to proceed with an administration withdraw.’” “