Is this just normal?

[thirdfromleft]

I am a bit concerned about my 3.5 year old, and wanted to check if this is normal for her age.

If something is out of place, she absolutely has to fix it and finds it very hard to move on otherwise. For example:

If the carpet threads at the ends are not straight, she will straighten them individually.
Her glass has to be in an exact position.
Her clothes need to be neatly stacked in a certain order after taking them off at bedtime.
If something is spilt, she will spend ages wiping it up. It's not enough if someone else cleans it.

Is this normal for the age?

I have an 18 month old DS who is just the same. He orders us to tidy things away and straightens things already. He's a very happy child but just very particular. I think it's just a personality thing. Wouldn't worry.