It appears to be a pecking injury that is now infected. You will need to perform some aggressive treatment to get it under control. Feel up to it?
You will need to be prepared to wash the eye with saline and treat it twice a day with Terramycin antibiotic eye ointment or Triple antibiotic ointment.
But the first step is the most difficult but must be done. The swelling is likely pus, and it's risking her eye sight. It needs to be pushed out of the eye. You start at the beak and push the pus out of the eye. It will be semi-solid like tooth paste or soft wax. After doing that, you should be able to see her eye, and she should be able to use the eye.
Continue the daily washing with saline and 2 x daily ointment until eye is completely healed.