We keep wondering if one of our chickies is a roo because she's bigger than the rest and her comb is getting red faster than the others. But she's also really passive and her tail feathers grew in really fast. S/he is about 6 weeks old now. When will we finally know for sure (and how)? My daughter has really bonded with this one and is really worried about it. By law we can't keep roosters in Oakland where we live. Thanks!