Well I do know how to introduce a hen to a flock.. but how do I introduce her to a Rooster

[badboyk1n9]

I think this says you have 3 females and one male and you are trying to add a fourth female. To me the numbers are irrelevant but I would like to know the age of the new girl and the boy. Is the new girl laying? Maturity could have a lot to do with it.

If both the boy and the girl are mature, the typical way a rooster adds a new hen to his flock it to mate with her. She may squat for him or she may run away and he chases her to force her. As long as they mate and no one is hurt all is good. It doesn't matter if there are 2 hens in his current flock or 20, he will meet the new girl the same way. It's possible to get a hen that will not accept the rooster as the flock master, even if both are mature. That may be due to the hen having a very strong personality or the rooster having a weak personality. Sometimes this can get violent so you need to watch.

If the boy is an immature cockerel he may not have the strength of personality to impress a mature hen. She might fight him but from what I've seen most of the time she runs away from him. He might chase her and not catch her or he may catch her and force her. If she is the immature one a good rooster should not try to force an immature pullet to mate but not all roosters are good. If both the boy and girl are immature about anything can happen.

There is also the possibility that a rooster may see a new chicken as an intruder, even if she is a hen. While "most" mature roosters welcome a mature hen to their flock most does not mean all. Some take their duty to protect the flock to mean no strange chickens are welcome. Maybe there is something about that hen that he doesn't trust. Or, as someone mentioned, are you sure this is a girl and not a boy?

I don't know what is going in with yours. Even if I knew their ages I would not be sure. Usually I let them work these things out by themselves as long as no one gets hurt. That means you do need to observe to be ready to intervene if you need to. The more room you have the better your chances of them working it out with no one getting hurt.

Good luck!

Bro, thank you for your concern.. but the rooster is doing okay with the hen... as you said the chicken I think was immature because she wasn't laying and started rn, also after some chasing the rooster seems to be okay with her and also thank you bro