There is still not enough known. The vaccine does not guarantee no more spread nor does it guarantee no illness. What it MAY do is lessen severity for breakthrough cases. Bottom line, the vaccine is still considered experimental and is NOT APPROVED for school aged students. If the petitioner has so much confidence in the efficacy of the vaccine and her daughter is already vaccinated then what is she concerned about?  Leave others to make the decisions for their own children as she was able to do for hers, or find an alternative for educating her daughter.