She only gave permission because the principal lied to her by threatening her with jail time if the child ended up on suspension.
As someone who has been on the other side of the desk, it sounds like a mother who doesn't give a damn and has a totally out of control child.
Georgia Law is clear on this
http://www.ajc.com/news/news/local/student-truancy-can-spell-1000-fine-jail-for-paren/nQPb6/
...After five unexcused absences, a parent can be fined up to $100 and sentenced to 30 days in jail or community service, according to state law. The most severe cases are referred to Juvenile Court.