If you hit her back a little, like you should for a quartering away shot, she might have had a full stomach from the night feed and the contents can plug up the entrance and exit holes. I have had that happen. When their stomach is full it can push up into the lung area pretty good. If you get that chewed up vegetation floating around in there you might not get a blood trail.

I made what looked like a perfect quartering away shot on a buck once. When I got down and found my arrow, it had green goo all over it and some blood.I left and came back a few hours later and found him within 75 yards. It was a perfect shot but his stomach was so full that it was well up in his ribcage. My arrow had entered between the 2nd and third last ribs and came out by his front shoulder. Passed thru both lungs, but not much of a blood trail either from the chewed up vegetation plugging the holes.

Hang in there man. This happens to us all if we hunt longenough. You didn't do anything wrong, the weather was just your enemy on this one. You made every effort to recover her. Something you learned from this hunt may help you recover the next one.