Given that you didn't knock her down, and she didn't tear out of there hobbled up... my guess is brisket. If it hit the elbow, I think it would have penetrated the chest. Possibly your shot was farther forward than you hoped. A brisket shot will bleed initially decent, then peter out. Typically they won't die from a brisket shot unless infection sets in... because no vitals are hit.
I'm quite surprised you found the ball... that's gotta be some long odds to find it at the point of impact. Strange.
Edit:
I just re-read your post....the only other thing I can think.... possibly you hit her far back and hit the last rib on the way out. ? That would explain the hunching/squatting. The only time I've seen a deer do that is when they are gut shot... they typically don't go far initially and hunch up. Then the intestines plug the holes, and blood is almost non existent as it pools up inside. They usually don't go far though and lay down. Since you didn't notice that you jumped her when you started looking, who knows for sure.
One of those two is my guess.
Last edited by WV Hunter; 12-21-2014 at 07:12 AM.