I'm no expert, but they appear to be Easter Eggers or Americanas. When you got them they looked about a week old, so they could be about 7 weeks old now. I'm bad at determining gender, at least until I get more experience. As to the "playing," I have seen hens kick and flap their wings like roosters at new comers, so they could still possibly be girls and are just establishing pecking order. JMO......
Dee
Raising Speckled Sussex, D'Uccles, and Silkies