Your "Dominant female" is telling the other that there is not enough space there, she'll die if you don't do something.When are they NOT in heat??? Maybe when delivering the babies? Males after them ALL the time!!!
I know my 20G is too small for much, but I do have 6 Mollies, 3" and 1.5", 4 females, 2 males. (was 6 females, but took 2 out). Two had babies, so were put into another tank. I can see that the Alpha male, Sailfin GoldDust/orange with green sparkly fins, who is extremely aggressive, is the head fish. He is the dominant one, keeps the other one hiding. So I probably will get many orange fish from him, as the other one tries to go to a female, and is chased away by the orange male. He is a handsome one, so no problems there. But having bred birds once upon a time, I can tell a dominant one for sure.
I think if I had a larger tank, there wouldn't be any sparring, but for a small tank, you have to live with the extra cleaning and heavy bioload to keep the water sparkling. It is clear now, and all the 10G tanks, too. Never had a problem with the 10G tanks, once I learned what cycling is, and how to do it. Thank you for all the tips, and I am getting better at it now.