I highly doubt that she bled to death from a small wound on her comb. When I dub my males, their entire comb is cut off and they lose a loooot of blood, but they walk away as if nothing happened, never showing signs of fatigue. She might have bled to death internally if she was attacked. Whatever the case is, I'm so sorry for you loss. *hugs*
PS: flour stops blood very effectively. So does cayenne peper, which, ironically, also relieves pain. Ice will slow blood flow as well.