BEHAVIOUR: Is my hen being a bully? please help!!

My guess would be to remove one of the hens, either Daisy or Dora. I dont tolerate violent behavior like this among my birds. As long as no blood is spilled I dont think too drastic of measures will be necessary.

When I got my Americaunas, my JG Dragon would pick on them incessantly. I separated them for about 2 months to allow the Americaunas to get a bit larger, then reintegrated. The pen they were in had a full view of the other hens, so everyone had a good eyeful of each other every day. Remember though that removing one bird can upset the pecking order. Sometimes a permanent removal is the only course of action because reintegration may not work.

There is still some nitpicking, my littlest Americauna is always being chased, but she has a full crop at night, so i know she is getting food.

I also put in 2 waterers and 2 feeders away from each other, so when the dominant one has its back turned, the submissive one still has a place to get fed and watered.

When giving treats, I spread them out all over so that no one place becomes the main treat area. Again, this prevents the bigger bird from focusing on the smaller bird. They cant be everywhere at once.

And yeah, your Roo should be doing something to prevent fighting, but you have to remember, it is in a chickens nature to be this way. They are birds, not people and dont have sympathies or empathy for each other. Pecking order is important in their lives. Like a bunch of high school students, you will always have a bully and a wuss.