Looks like a several wrapped up membranes along with pus.Update: this is the mass cut open. Also I have aqua-mox arriving in the mail tomorrow. Blanch the patient is doing slightly better. Trilling and purring at me but not drinking water or eating on her own. I’ve had to administer water through a syringe to keep her hydrated. Fingers crossed things look up!
Do you have photos of her, how she stands and her poop?
You mention you have her in quarantine - for this or something else? Is she able to move about at all?
I'd definitely start the Calcium if you haven't done so.