Whether you try to help her out of this habit yourself, or perhaps find professional help to help you work through it and understand it, I really hope you will continue to try to get a handle on it. I would think you would have a better chance at removing the habit now or at the very least finding a healthy coping tool early on while she's young, while this is still a relatively new habit.

It's a tough one though. I have had this issue, and still the need to pick arises every once in a while and I get flung back into old habits, but it's much better now, I don't do it nearly as often as I used to. But even after a lot of time thinking about it, I don't know exactly why I do it/why I did it. I have a few ideas as to why, but even all those reasons added up doesn't completely explain it..