The first one is a lady, the second one is a male I *think*, the third is a little hard but I think they're also a lady, it will be easier to tell for sure once they are a little older before they need to possibly be separated !
They all three look female to me. The second one is harder to tell. By 4-5 weeks old, balls should drop, then you can tell for sure. In that case, you'll need to separate immediately, and get a friend for the lone one. Hope that helps!