Was she looking at you when you shot?
If a deer is watching you and sees the limbs fly forward it can react to sight instead of sound. At 16 yards it would have about .16 seconds to react before the arrow got there from a 300fps bow, if it reacted to sight.

I've found (my personal experience only)with a 250fps arrow @ 30 yards a deer can have time to drop a few inches before the arrow hits, but with a 300fps arrow the reaction is much less - if any.

I have taken my crossbow along when merely observing deer at a feeder and shot (not at the deer, just into the ground beneath the stand) to see reactions. At out to a45-60 yard rangethe deer usually react to the shot, not always running off, but they usually move (duck - or "jump the string"). Beyond 60 yards or sosome react, some don't. I've seen them continue to feed without even looking up! I know they heard the sound, but I have a therory that each deer has it's own "danger zone" which it reacts to. They hear a lot of noises where I hunt in a rural area. Traffic in the distance, sirens, dogs, shouting, loud talk, machinery,etc. I tend to believe they can become somewhat accustomed to noise and don't react unless it's close (in that "danger zone")in a lot of cases. Another factor to throw in is the question of whether any of their other senses have detected danger. If they smell human scent nearby they may not run away, but simply go into an increases alert mode. If they hear an unnatural noise or see movement then,it may be enough to make them react instantly. It may take two or three senses detecting danger with some deer! I have had a button buck at the feeder when I walked into the food plot 15 yards from the feeder. He looked up, then went back to eating. I went to my stand 70 yards away (across the open food plot)and he watched me climb in. 20 minutes later he was under the stand eating acorns! No, I didn't shoot him - we even cautioned other hunters allowed on that property to leave him alone. He was either very brave, or very stupid!

One year I was checking the sights on my muzzleloader before gun season opened. We have a 100 yard range, but I wanted to check it at 200 yards so I had to move the shooting benchback to a point where I was about 70 yards behind where our deer feeder was located, and the bullets would pass about 15 yards to the side of the feeder. Imoved the bench,but had to leave before I got to check it at that distance. The next morning I resumed my shooting and since it's on private property and there's a good earthen backstop behind the target I just went to the bench and visually observed there was nothing on the range. I fired a 3 shot group, then started out to pull the target I had left from the day before. The feeder was behind some low brush and not visible from the shooting bench. When I got to the edge of theold fencerow and could seethe feeder there stood a doe munching away at the corn! We shoot on that range year-round and I'd say the local deer have learned to ignore the noise.