Aggresive Blue Silkie? :/

[PoultryQueen29]

My 4 month old blue silkie is chasing and nipping at my white and splash silkies. The splash silkie is being chased the most though. What concerns me the most is my splash is small and light. I don't know if that is because the blue one is not letting her eat or she is stressed by being chased constantly. It is also possible she is just smaller or the breeder made a mistake about her age because she looks very healthy.

Is it possible that the blue silkie is a rooster and is trying to mate?

Here are pictures of all 3 of them:

Blue silkie

Splash silkie

White silkie