I love what Rabbit said!
Whenever the topic of 'anti-style descriptors' comes up, almost everyone on the forum lists 'cute' as something they don't want to be. I completely understand that, and if I worked in a traditional job I'd be aiming to avoid cute as well. But for my current lifestyle, I find it much easier to just work with my inherently cute elements (small size, round face, etc.) than against them, and just enjoy the clothing I like despite its 'cute' associations, because it doesn't matter if people underestimate me at first glance. In fact, I like being more approachable in a lot of situations, as I've been told for most of my life I have an intimidating personality! At first I was nervous to post outfits, thinking all of those who didn't want to be cute would not be impressed with my style, but instead the forum's been incredibly welcoming and supportive.
Yes, it is a shame when our preferred silhouettes/clothing items have connotations we don't particularly care for. I find it annoying that full skirts are considered little girl-like, when for most of history women have worn such silhouettes. Or that pointy collars are considered grown up & serious/business-like while round ones are childish, even though my round face & short neck look a million times better in a flat round collar (aka peter pan) than the ones you find on traditional button up shirts. Luckily, I can ignore such social assumptions for my daily life though, and adjust my clothing accordingly when I need to make a different impression!
Anyway, my point is that if you feel comfortable in dresses this length, and it doesn't impact your life if some people think it's too short, just enjoy them. The outfit looks lovely on you!
(For what it's worth, my mom is turning 54 this year and wears her skirts above the knee, probably around this length, with small heels because she prefers the proportions-she's 5' 1". She never looks inappropriate in my eyes!)