The bullying won't stop, HELP!

We put our big hens with the 8 week old chicks and keep them seperated but could see each other and supervised visits during each day. 2 of the big hens did not like the chicks and bullied, but 1 which is head hen was down right mean, holding done and pulling out feathers and eating them! I moved her out to the small coop for 5 days and was forced to move her back last night due to weather and she just picked up where she left off! Because of the weather they have to be in the same coop, my husband is ready to have her for dinner, do some hens just not except new chickens? I thought maybe since we introduced the big hens into the mamma and 8 week old chicks turf instead of the big hens turf it would work out better but nope! Any suggestions?