Well, I just had a vague explanation written up (I'm not vegan/vegetarian, afterall) but then my work Internet decided to complain about my passwords and wiped it all out, so I'll write up an even more brief one. It isn't so much "killing of living things" as the fact that thinking, feeling creatures are being raised (often in very poor conditions) and killed (often inhumanely, from what I hear from the people working in meat processing plants) to provide food when (in today's world, at least) humans don't actually NEED to eat meat, with a few exceptions regarding allergies and digestive disabilities. In her mind, the desire for leather is just one more reason these animals are being raised in horrible conditions and killed inhumanely. She does have to wear normal shoes because we can't afford the vegan alternatives (except really crappy plastic shoes, and she's on her feet all day, so that won't work), but those are something she has to accept for the time being. My sheathmaking/pouchmaking desires are a hobby, not a necessity, and they can be done with cheap alternatives like Kydex and canvas, so she doesn't see any reason why I should need to use leather. That's the best I can explain it, being quite non-vegan myself. Thanks!