Well, I have no way or means to separate her from cockerels. I haven't ever done that or knew it was even a suggested thing to do. I have other Black Coppers she isn't the only one.please do not breed your gorgeous BC pullets yet ,she need to be separated from the cockerels ,so she can keep growing to her full potential .
marans are slow maturing and if pullets are kept with cockerels ,that will stun they growth .
she need to reach 2.5kg minimum to mate her to cockerel . other wise she will never grow properly .