Two hens, one is pecking at others head

[GreenCh1cken]

I'm a new chicken mama and I have an issue. I have two hens, 10 months old, and in the last 3 days one of them will not stop going after the other. she pecks her on the head. When I let them out of the run and they are free ranging the bully will come up for no reason and just tag her. I have placed added treats for them during the day, recently added 20% layer feed cause I heard there might be a protein issue, and on top of that I applied some anti pecking lotion to her head but that didn't seem to work. My question is, will this behavior continue to go on or just a phase? Should I try those pinless peepers? Should I just seperate them completely and have them live in their own quarters? They have turned into my pets so I have no interest in "offing" the bully.
Please help, its stressing me out as much as my poor hen that is getting attacked.

 

[rosemarythyme]

Just the 2 birds? Any photo of your layout, coop and run? How often do they get to free range?