one hen is picking the feather's & combs of the rest of the flock.

[Gennasgems]

This is a mixed breed flock of 6 that has been raised together for 1 1/2 years. I gave away her dominant sister a couple days ago because she brought blood from pecking at a lower slower one. Now her sister has started picking at that one's feathers and another ! I have her separated . How long must i wait to bring her to the bottom of the pecking order?