Children survivors of brain cancer

Hello - I'm looking for feedback regarding children that survived brain cancer with radiation and chemo.  Any noted side effects 2 years later and how the child is doing in school.  i now have a  grandaughter in my care since September and it seems to me that she is unable to focus at school or at home and unable to memorize her math tables, etc.   At home she searches for simple words for a conversation and cannot follow basic instructions too well. When she started 4th grade I told the school that she needed to be thoroughly assessed as i saw several issues such as extreme short term memory.  I can see the school is not going to do anything and the teacher feels like she can do better and the cancer treatment is an excuse.  I dont know and would love to hear from other parents. She just received her report card and it is very bad.