So DD5 is reading chapter books at home and dead keen to move on to "fat books". Harry Potter etc

At school they are stalling her on 1 year in advance. She is due to skip next year so the stalling will see her start the year at the same level as the cohort she is moving into.

She can read these books fluently with no errors and with intonation on the first read. She does appear to comprehend the reading HOWEVER some of the subject matter is out of her sphere of experience. For example she read a book about daring someone to be naughty. Well she doesn't know about being dared so of course asked the teacher to explain it to her.

The teacher has acknowledged DD comprehends just fine but feels that it is useful to keep using these books to expose her to new ideas which she doesn't comprehend yet. We only have 5ish weeks left, should I push for a higher level or let it be. She is reading whatever she likes at home but I know she would like to do other things at home as well as reading but she feels the need to "catch up" outside of school time.