I’m sorry that happened. I have ‘t seen a wound do that before. Is there any way she could have hurt it more or pecked it? I wonder if it is a hematoma that was leaking? I am going to tag @azygous who has seen a lot of strange things in her years with chickens, to take a look at your pictures in post 6 and 8, and might know why it swelled and started leaking blood.