RE: animals feeling....
Some people just haven't had the privilege of hunting and don't understand what it's all about. Tell her you're doing the majority of the deer a favor by eliminating competition fora limited supply of food sources. Ask her if she'd rather see deer die a slow death from starvation, cold,getting hit by cars, etc. as opposed to a well placed shot through the lungs or heart. If that doesn't work, cook her up a nice venison steak, that'll change her mind.