True. I've always wondered that. You couldn't get away with it here in a British school.
Surely it would have been better to have Ax pose as one of the Animorphs at the school? No random extra relative, no new kid at the school, no reason to draw suspicion (providing Ax can hold himself together).
If Ax IDed himself as an Animorph, wouldn't Chapman jump down his throat?
The only thing I have found so far on the subject of kids bringing visiting relatives to school is the following from the Marshal Public Schools website about its summer school program. I'm assuming that the below policies would apply to the regular school year as well.
Program Visitation by Students not Enrolled: At times, summer school students desire to bring an out-of-town visiting friend or relative. Visitations are allowed according to the following guidelines:
A non-enrolled student may visit the program for a maximum of two days.
Parents of children who are bringing visitors must call the summer school office one day prior to the visit to state that their child is bringing a visitor.
Student visitors to the summer school program must check in at the building office upon their arrival.
No student visitors will be allowed to visit a class where a field trip is occurring in the class on that day.