Awe,,, don't do that just yet. When I introduced my six week old Buffs (3 of them) to the 9 week olds buffs(5 of them), I was going through the same thing. The older ones would peck and torment my babies, never hurt them but I thing to let them know who was boss. Stressed me out something awful, but stuck it out. It's now going on four weeks with all eight being together and things have finally settled down. They are now three months (5) and two months (3). I have one who still likes to play the bully, but honestly, I think she is the one who is becoming the leader of the bunch. All in all I'm very glad that I didn't give up on them...
I don't know what your situation is and if their hurting your baby (hope not), hopefully you won't have to give her away. I got a lot of good advice on my situation through this forum, I hope you do too. I hope it all works out for you for the good. Good luck.......