DD is nearly 7. I have wondered in the past if she might be a bit obsessive but have just put it down to kids being kids. I would say that DH is a little bit OCD. He does lots of things that I didn't even think the kids were aware of, like tapping the wall before he walks in to a room. Or tapping the rim and the underside of a glass/cup before he drinks from it.
I just had a very laid-back conversation with DD where I mentioned this and she said that she notices all the things DH does. I tried to explain to her what the word compulsion meant and I asked her if she ever feels like that. She said that she does, lots of times. It all seems to be centered around her room and bedtime. So things like if her door isn't closed in a certain way, or if her curtains aren't closed properly, or if she notices that certain things aren't positioned properly. I asked her how it makes her feel and she said that it bothers her to the extent that she has to get up and do something about it. I asked her how she would feel if she couldn't get up and correct whatever it was and she said that she wouldn't be able to sleep and that she would keep thinking and thinking about whatever it was and would just feel bad (anxious).
So, are these feelings normal for a child, or is this something that I should be concerned about?