When my hen prolapsed, she would try to "poop" out the swelled tissue. I put Preparation H (A hemorrhoid cream) on it, and she didn't have any problems after.
That blob of fat may be the actual crop, can you include pictures? You may also have to do something to keep the flaps together so that they heal properly but it may not be that bad.
It looks like bumblefoot to me. Here is a link for instructions on a non invasive treatment. Even if it isn't bumblefoot, it will not hurt her. There are also many other threads on here that you can look at...
I am not familiar with the effects of penicillan other than it is an antibiotic, but I know that ones like Tylan and other broad spectrum antibiotics have worked for others and me. Good Luck!
My chickens do something that looks like the top half is scraping the bottom, if this is what yours is doing, my chickens have done it their whole life with no problems. Check your other chickens and see if they do it too.
If you won't remove the whole thing, I think you still have to cut off some healthy flesh to help stop the rest from dieing, like how doctors will amputate more than just the afflicted area to stop the spread.
I don't know if this is an option with you saying that the rooster is a huge factor in the protection of your flock, but I would try separating the rooster and seeing how she reacts. Her being very thirsty and hungry may indicate that your rooster is stopping her from getting to the food and...
I would try splinting it as soon as possible before it heals like that. I have never had to make a splint, but you could probably make a decent one out of 2 popsicle sticks and some bandaids. The sticks on the sides keeping the toe lined up and held in place by the bandaids.
I had mareks first go through my flock about a year ago, and I have had only 2 out of 6 go back to the coop after being brought inside. 1 relapsed and died shortly after being put back but the other has being doing fine since, lays eggs, and is near the top of the pecking order. Unfortunately...
Is she still ok? There are many things that it could be. Is she pooping? What does it look like? Can she stand or is she laying down? You can try some antibiotics. There are a lot of different kinds, but a feed store should carry a general one which is what you want since you don'y know what it...
Does he eat and drink at all? The feed stores around me sell a medication called Neo-Chlor which is a general antibiotic. Even if that particular medication isn't there, there will probably be another one, look for one that says broad spectrum or anything that indicates general use. I'm sorry...
I don't know if it is bumblefoot, can you post some pictures? Also, a soak in epsom salt water is supposed to help if it is. I have never had experience with bumblefoot but here is a link to a thread explaining how to cure it without surgery. Good Luck...
I have never had a chicken throw up the clumps while it is still impacted. If it is impacted long enough, it will likely develop into sour crop which when throwing up comes into play. Hopefully it won't come to that but if it does, there are many other threads related to it. After the lump...