Separating her is probably not helping. When you say you released her, does that mean she was in a different area for brooding?
Unfortunately it seems she's fallen off the pecking order. Are you sure she is being attacked and not just pecked a lot? Pecking, which will look pretty bad sometimes, is completely normal. It can be easily confused with fighting. These things need to run their course and it's entirely taxing on their mental health to keep restarting the pecking order situation. Every time you pull her out you're restarting it for her. Unless she is bleeding I wouldn't pull her out. I would also probably pull her out if they are going for her eyes.
If she is bleeding or they are being extremely aggressive, then we need to slowly reintroduce her to the flock. You can do this by adding another pen or cage of some sort, out with the others. They need to be in veiw of each other. This gives them time to get familiar with her face again. This can take two weeks - a month to work effectively.
Once you reintroduce her, they will still peck her, but it won't be as violent. However you absolutely have to let them sort out the pecking order themselves. Only stop them if they are pinning her down or drawing blood.
Also if she was with the others when she was broody, she may have made some enemies defending her eggs lol. This will take time to heal the conflict. She also may not be done being broody and may be starting the fights with her body language.
To replenish her, some scrambled or boiled eggs would be nice, some electrolytes for poultry in her water (and everyone else's for that matter). I use Rooster Booster personally. Also some poultry probiotics would be a nice touch.
She's clearly stressed going through this and being forced not to brood. Be sure to give her treats and attention. Stress is a silent killer. Go out there and just hold her sometimes (unless she's the type to hate being held). It really helps them to know they are not alone.
If none of this works, you can try the advanced separation method I use. Basically you remove some top level hens from the flock and add this hen back to the flock. This breaks up the pecking order massively and gives her a good chance to get back in. The others are alpha hens and usually make their way back in the order without too much pecking, when you add them back. There's all kinds of different tricks for pecking order problems. You can also just add one alpha in speration with her and let them become friends. When you release them together they will help each other not be victims.