Hi Anaya,
If you have any nests in the cage, you need to remove the nests. You can’t give them nests or let them breed if there is more than one pair of birds in a cage. If there are no nests, then you need to remove the aggressive female and maybe get another male for her. It’s not a good idea to have an odd number of birds in a cage, regardless of sex. They tend to pair off and one bird gets left out. This single hen is trying to steal the other bird’s mate. She is not going to stop. Possibly your cage might be too small? But mostly you have an odd number and this female wants a male.
Thank you for asking Lafeber,
Brenda