Sometimes when they get bumblefoot the infection can “travel” or “tunnel” and even tho the entrance is in one area, an area of pus, or infection, can pop up a bit away from the entrance. Looks like that may have happened here. I had a very similar experience with one of my hens.
It sounds like you’re doing every correctly. It will probably just take time. I would keep soaking, treating with ointment or prid and wrapping, to keep the area soft. Then if you feel up to it you could apply a bit pressure to the top of the swelling on her foot and push towards the point where you extracted the kernel. See if you are able to extract any pus out of the entrance. Again, this may take a lot of time, but keep at it and don’t be discouraged. If at anytime things start to look worse, though, don’t hesitate to seek out veterinary care if possible.