I recently aquired a Bantam hen with 6 two weeks old ckicks. I have an existing flock of buff orpungton 10 week olds mixed with 8 week olds. All are hens with two 8 week old roos.
Can i add the new hen n babies to the existing flock??
Oooo, that's gonna be a tricky integration!
I would keep the bantam broody and her babies separate for now, maybe always.
How many chicks in your existing flock?
How big is your coop and run, in feet by feet?
Dimensions and pics would be most helpful here.
It would be good to know what you have to work with, mainly how many and what sizes of coops., runs, and shelters. How are they tied together.
In general I have a different opinion, provided you have sufficient room. Those 8 and 10 week old juveniles are almost certainly going to be afraid of that broody hen. I'll use weasel words like almost because you can never be certain what will happen with living animals but I'd be surprised if she had any problems at all keeping them away from her babies. If you have enough room I think it will take almost no time for those juveniles to learn to give that broody and her chicks a clear berth. This part of the process shouldn't be too bad.
At some point that broody will wean her babies and leave hem alone to make their way with the flock. That could happen in another couple of weeks or it could be a couple of months. That is when I'd think it might get interesting. You will have one adult hen, that bunch of juveniles (however old they will be then) and those six chicks. There is no telling what will happen then, not with living animals.
As long as you have adequate room, and that includes sleeping space, I would not expect problems with the six chicks. By then the others should accept them as flock members but I'd expect the chicks to remain in a sub-flock and stay by themselves. I know they are bantams and I don't do bantams, but I do this all the time with full sized fowl chicks with older adolescents and grown chickens. I have a lot of room, inside and outside.
Having a single adult hen in a flock with several pullets and two cockerels when the hormones hit the cockerels will probably be where your drama comes from, if you have any drama. The mature hen will be dominant. Those cockerels' hormones will be telling them to be dominant. They may work that out really peacefully, I don't know. But I would not be surprised to see some violence between them. I would not expect much of a problem between that bantam mature hen and those pullets with those cockerels there. With living animals I sure can't give you any guarantees but this is how I'd try it.
Any time you integrate have a Plan B ready. You just never know.