It's either out of boredom or nerves. Keep her hands busy most of the time with playdoh, toy cars (yes for girls!!!), coloring, threading string through cardboard design to make a picture, toy bowling, any zillions of hands on activites. If she's calm and not more temperamental than the usual 3 year old things, I wouldn't be worried about it.
at 3:25 PM on Jan. 10, 2010