There can’t be dumber chickens than Polish. Sometimes going back doesn’t necessarily mean stupid as she may not be as far down in the pecking order as “You” think. If we had all aggressive birds there too are problems and constant squabbling as everyone wants to be top bird. I say let her set and raise chicks. She might surprise you. A hen who is a good mom and can grow chicks out is sometimes more valuable in the long run than lays eggs and kills her babies or leaves them to die off.