Help with chicken health

We think this Australorp chicken is getting picked on by our rooster (bantam). They are all about 3 years old. The eye on the other side of the black hen is normal. I see a little bit of dried blood on the rooster

Rooster has picked on her in the past but we thought it stopped. 7 chickens to 1 rooster.

Looking for options and suggestions please. First 6 months of raising chickens and still learning. Chickens came from a good friend farm.

Thanks for any help.