would you double check with the teacher or will I be seen as a competitive mother?

[xxwowxx]

my dd came home saying she moved to another reading group, although when I asked her who is in her group she still says most of the kids who used to be in her group. It seems that the teacher of her group changed, but dd thinks she was moved down a group because of that. Should I speak with the teacher and double check which group she is in or will the teacher see me as a competitive mother?

I'd ask. I did when dd1 said she moved in literacy and whatever my dd's teacher thought, I really didn't care :) Plus, I'd like to know why anyway so that I can (maybe) help from home.

Do the classroom groups have anything to do with the parents? We don't get involved in which side of the whiteboard the teacher prefers to stand at, do we?

well if my child moved down a group I think I have the right to know. It is my child after all! So whether she actually moved down or not I should know!

I would maybe give it a couple of days. It might be a one off or a special assessment kind of grouping.

It may well be that more kids have moved into the group she is in so it has been split in half so she hasn't been moved down iyswim.

Yes I would want to know, I want transparency I want to be able to ask questions without being batted off or thought of as the pushy parent.

But how do you know that it is moving down/up? If she is still reading at the same level as she did before is it really an issue to raise??

A child moving 'down' a group doesn't necessarily mean they haven't made good progress. It may mean that other children have excelled their progress and are therefore working at a more able level than your child.
I have done this today (maybe you're one of my parents?). I have two children who moved down because they are better being more confident with quieter children than having to compete with those who are more outspoken. Also one of them is an extremely able reader but very slow, which slows down the pace at which the group reads. Another child moved down because although his reading level is at the required stage for Y2, his comprehension levels are below and therefore needs a book that is less challenging on the comprehension side of things.
As long as YOUR child is making good progress, I wouldn't worry.