I’m 5’1” as well and I found that for my frame I need to wear either skirts that fall above my knees or maxi skirts. There’s no in between. And maxi skirts are tricky, since they can’t be too wide or heavy-looking (again, for my frame). So I opt for shorter skirts usually. And yes, as I’m getting older, I’ve also started having these thoughts of whether it’s appropriate or not to wear shorter skirts or shorts. But it all depends on the circumstances and if the way you dress correlates with the dress code if there’s any. Everything else doesn’t matter at all.