"falling behind academically" makes sense only if she alone is taking a leave. If whole school is closed then she is keeping with the school. In a 70 year lifet

"falling behind academically" makes sense only if she alone is taking a leave. If whole school is closed then she is keeping with the school. In a 70 year lifetime, taking at worse 3 months of holidays won't affect anyone in life. She'll have a more severe scar if she infects anyone who struggles for life. With internet and access to online courses find something that helps her self study and improve upon the existing knowledge/skills. Follow the instructions from school.