Yes, she may gain more weight afterward, but at 8 months your White Rock should have reached her full frame size.I lost a beautiful White Plymouth Rock who was big, so I bought 2 chicks. One is a White Rock and one turned out to be a Delaware. At 5 months my White rock is smaller than the Delaware. Maybe she is a slow grower. Are we looking at 8 months for a White Plymouth Rock to be full grown? Thank you.