Here's an experiment for you. And to be honest, when I suggest this to people they do often start to see my point.
Next time you are out somewhere with lots of toddlers at the kind of activity where you would expect them to be dressed for comfort/practicality and it's a bit cold (so probably more of a winter than a summer thing). Look around and compare the outfits of the girls vs the boys. what you will find is that the boys are usually wearing practical, comfy, trackies or loose fit trousers. They might be in jeans or cords, but they'll be straight cut/baggy jeans.
Then take a look at the girls. Many will be wearing similar to the boys. Or they'll have gone "girly" and will be wearing leggings/tights with shorts/skirts over. But a lot of them will be wearing just leggings with a t-shirt/jumper. Or if they wear jeans, they're jegging style.
And I ask myself, why is it that when a parent chooses to put their child in "comfy" clothing, the GIRLS clothing is always snug and the BOYS clothing is not.
And what I came to realise is that from when they are super small, we tell girls that short/tight clothes are "normal", even when we are not sexualising them.
As for your examples - of course she wears shorts in summer, as do boys (although I did work very hard to de-normalise much shorter shorts for her than for the boys. She does have some shorter "girly" shorts now, but she actualy prefers shorts that are a bit looser as they're more comfy for her). Tights and skirts are fine too - but actually, she hates them!
Having said that, while I am not trying to insist on particular types of clothing for school, I find it mindblowing that skirts and tights and impractical shoes are still standard for girls at school - in my day we fought to be allowed to wear trousers to protect us from the cold. (And dd's school shoes have always been proper shoes not ridiculous pseudo-ballet shoes that do F+++ all to protect her feet).
It infuriates me that girls clothing, even when youjng, is so often LESS practical. Trackies are WARMER than leggings but we put them in leggings? Why? Most girls school shoes barely cover the feet so they get wet. Why?