I have three platy. The one female that is larger than my male and my pregnant female that is yellow and white, my male is a yellow long finned platy, and the pregnant one is a white mickey mouse platy. The bigger female picks on the mickey mouse platy and the male platy from time to time. My pregnant female is in her own spot in a breeding net inside the aquarium and she seems much happier being in her own space. Since I moved her the dominant female doesn't pick on the male as much now.
The dominant platy doesn't pick on the
neon tetra or the glow fish or the cory cats just the two other platy. But like I said she has mellowed out a bit now. Maybe it was a territory thing when I first put the new platy in. pecking order so to speak. So now I am just waiting for the fry to arrive.