Introducing one pullet to the flock

[Naisha]

Hi! I have been given 1 pullet today, a Sussex. I don’t know her age but she’s not too small.
I already have 2 big girls and 4 bantams. Right now the Sussex is at the run next to the existing flock run. The first contact has been intense! The big girls seemed curious but didn’t want to get close to the new one. The cochin bantams went to see the new one right away and they were all “You came to the wrong neighborhood, madafaka” attitude. The sussex was not shy at all and looked like she wanted to fight. They even bumped their chest through the fence and move their heads in a threatening way.
It’s the first impression, but do you think it’s a matter of time? I plan to keep them that way for a couple weeks and then open the door. What’s your experience with “sassy” newcomers? And with not too welcoming chickens?

 

[BlindLemonChicken]

I wouldn't put a new bird up next to my existing flock because of the risk of disease. New girl should be quarantined for a few weeks well away from the others. But as to your actual question, that all seems normal for a fast intro. I do a bigger distance where they can see but not get near each other at first. My regular coop is on one side of a chain link fence and its inside a dog run so new girls go in another coop on the other side of two sets of chain link. Not everyone has the space for that but slower is better when it comes to introducing a single chicken. My Specks are my boss chickens but I haven't had others so your new girl may be typical for a Sussex and boss is just what she wants to be in which case you will have to go slower anyway so she doesn't beat up on your bantams. Mine have never caused damage but the one time I did an intro too fast with them and a pullet the pullet injured herself trying to get away from them

 

[Naisha]

Agh!! Ok yea I don’t have any run that is further from there. But I can improvise a double fence so they have more space between their areas. Thank you for your answer. I’ll go slowly

 

[rosemarythyme]

Agh!! Ok yea I don’t have any run that is further from there. But I can improvise a double fence so they have more space between their areas. Thank you for your answer. I’ll go slowly

No point in worrying about quarantine at this point - they're already exposed and anything she has they have.

But yes doing a gradual see but don't touch so they can get used to each other is your first step.