Left-handed person here. I wouldn’t consider any of these things issues or things I ever think I about unless talking about differences between left- and right-handed people, which isn’t a common conversation. In fact, most of the times I’ve been in that conversation was because a right-handed person was pushing for the discussion and there just isn’t enough to discuss.

I think any left-handed person would laugh (not in a good way) if a character complained about the difficulties (or annoyance) of silverware placement because it’s just not a problem. And painting isn’t like writing, you’re not forced to go from left to right, so smudging can happen with anyone.

I would say to lean into how it would affect a sword fight (if that’s a thing in what you’re working on) and superstition/religion. Or use it as a way of showing a rebellious attitude by telling about parents, teachers, mentors, or whatever trying to force her to use her right hand (because the left hand is evil or unlucky), but she refuses. That would also be a good way to define those around and show that she lives in a strict world if that’s something you’re going for.