left handed?

We keep wondering about Gretchen's hand preference. She used to draw with both, but always switch the chalk or crayon to her left hand for her more detailed work. When she writes letters now, it is most likely in her left hand. And today, I watched her paint with a small brush in her left hand. But, she does sometimes create things with her right hand. She sucks her left thumb, too. So, when does the hand preference really show clearly? Is she old enough for me to make a prediction yet? Or is she still discovering her own abilities on this?

Wikipedia claims 7% of the population is left handed, but that it is more common in fraternal and identical twins on this page. It also says statistically, more left handed people are born to older mothers. Did I tell you someone in Walmart recently asked me if Gretchen was my grandchild????? But, that is getting off topic here.

I guess I should ask my best friend who is not only a leftie, but also a science teacher if Gretchen is old enough for us to have a hint about her handedness.