I hate to say it, but I think she has more going on that that abcess on her head. I thought her beak looked strange when you posted the other night, now I see why.
You are doing such a great job with her, I hope she comes around. maybe try some yogurt with some crumbles in it if you have some, even chick starter would be good. It is easy to digest and I feed it to my sick birds when they are starting to come around. A little apple cider vinegar is good in her water too to help keep her gut in shape. Every little bit helps, I think.
But one thing is for sure, that huge lump has gone WAY down. She has to be more comfortable than before you started treatment.
Good luck, lady.
Oh, and how is the other lump looking by hear earlobe?