Why are you making this poor child introduce herself to all these stangers? Harry should do that. And why has he never introduced himself as anything other than "grandma's Friend" wouldn't a relative be more comforting.
Weird Transportation again. but others have already commented on it.
Where does Teddy go to school? Wouldn't it be more convenient for them to go the same place?
A suggestion... if you still want him to go back to the school he attended as a child, have him go there to unenroll her or have her records transferred to her new school.
Also if he wanted to know the day classes start he should have asked the headmaster I know I wouldn't have known that information at six. I didn't learn how calendars worked until second grade.