T.P.
I'm a pediatric physical therapist, and I will tell you that kids do many strange things while developing, some of them could signal a problem, but often not. Worst case scenario...anytime you notice something is odd with movement on one side of the body it should cause you to watch closely, because it COULD indicate a brain problem. Really, though, if you are not seeing any other one-sided problems, it is probably nothing. I would definitely bring it to your pediatrician's attention, but I think you would be safe to watch closely and don't need to rush there today. If you notice it worsening at all or she has any problems with her left arm too, then rush, but you may find she will fix things all on her own. Some things to watch is pulling up to stand. Does she use each side equally to pull up or only the right leg? That might indicate weakness on the left side. Can she walk around furniture yet? If so, does she go to the right and the left? Please keep us posted on the results! Good for you for noticing!