Oh, i'm so sorry to hear that your pair is having issue getting along.
It's not unheard of, but it is pretty rare, usually the males do take good care of their mates while nesting.
Years and years ago, this happened with one of my dad's breeding pairs, and the female didn't not survive the attacks, so it's a good thing you separated them.
If your hen only has one chick to look after, I'm sure she will do just fine on her own. Do not put the male back in, or you may lose both the hen and the chick.
In the future, do not allow this male to breed again.