If you found a pile of blood...she had either laid down or stopped. If she laid down within 50-75yds of being shot, she's probably hurt real bad.

Could be liver...which is deadly. The gutshots I've dealt with haven't bled enough to make a pile.

It could have been a one-lung hit, also. I've shot deer through both lungs and just had red blood...no bubbles.

All you can do is look, look, and when you're done looking, look some more.