Breed ID

[KM2H]

It's a hen. A rooster at this age would have male specific saddles.

It also sounds like you didn't quarantine or do a slow integration. If so, the no integration would be why she was getting chased.

In the future, make sure you quarantine new birds well away from your existing flock, for a minimum of 4 weeks.

I did totally risk it because I didn't have a place to keep them separate and that I have to work on and prepare for.