This was on my kids summer reading list for 7th grade so I thought I would read it.
I don't think much of "A Wrinkle in Time". A good start and a rushed ending. No character development. Even one my daughters was unimpressed.
I am sorry if I'm stepping on the toes of some of you with fond childhood memories of this story but this is an incredibly juvenile story. Third grade at best.
If you're a middle school teacher I would suggest dumping this and looking very hard at "The Ocean at the End of Lane" by Neil Gaiman. Both of my 'middle-schoolers' really liked "Ocean" and read it in the 5th grade.