You mentioned that this was your first hunt. I'm not trying to critisize her, but offer some advise.
You said that you found several pools of blood. That's a sign that the deer was stopping & bleeding while he was either standing or laying down. It sounds like you were pushing him. Next time, back off & wait at least an hour (a few hours is better) before you try to track the deer. If he is hit with more than just a flesh wound, he will lay down & die or at least stiffen up enough that he won't be able to get up & run off easily when you do approach him. Try to get a buddy to help track him. Go slow & one of you watch the track while the other keeps looking forward to catch him still laying down if he isn't dead yet.