I think you are right, those look like pin feathers.
Here was her neck you can see the pin feathers some:

Some look like little paint brushes, you can see the black on the ends.
I guess they are called "blood feathers" (from the research I did on here). I guess if they don't stop bleeding you have to pluck them out or the bird could bleed to death, but I was told to just leave them and not pluck them as they quit bleeding. Her tail feathers are growing back in now, so it is good. It was very scary though!I would be worried about that blood. Do chickens bleed when they moult?
Here was her neck you can see the pin feathers some:
Some look like little paint brushes, you can see the black on the ends.