Thanks for your replies!! I was concerned that the timing was really bad or that it was causing mother hen stress. Am relieved to hear its ok to leave them together and that she will mellow in a bit :)
The 2.5mth olds are too quick for her to catch but she's super fierce to them. Chasing them if they are in her line of sight. She stops once they hide behind an obstacle. Maybe because of her new chicks? She's usually not too aggressive.
Ok here's the background. We started with 2 hens, a polish and a standard silkie, they are good friends and now about 9months old.
Our polish became broody and now has 4 chicks under her wing. They hatched 3 days ago. They are currently in a double nestbox in the main coop.
Before she went...