Re: Could my 4 year old have OCD
Does she have intense anxiety if she doesn't take the opposite route? If so, then it may be possible, but at that age there isn't much you can do except talk with her and possibly CBT. CBT will be hard for her to understand though. Anyway, I wouldn't get worried about it until she starts showing signs of anxiety which she most likely never will. Poeple can have an obsessive personality and not have a dissorder. A dissorder is characterized by the inability to not do the compulsion and severe anxiety reaction due to not doing the compulsion.
Have you asked her not to go the opposite way? Also, aske her why she goes the opposite way? Try to get a good ansxwer out of her, not "I don't know". If it is OCD then there is usually a negative thought that coincides with the compulsion.
Don't get worried yet until you explore it a little further.