OP - I spend SOOO much time thinking about this issue and going round in circles
Of course girls should wear whatever the like with no comment from the rest of us....but also, why is it that "empowering" girls requires insanely short skirts, boob tubes and trousers that are sprayed on!?
The closest I've come to a conclusion so far is that we can't and mustn't comment or judge girls for their choices.
BUT, that it's totally okay for us to continue to push back at a societal level to say that this shouldn't be the norm. Because much as girls THINK they're making these decisions for themselves, they're not - it's part of a much bigger subtle message they get about how to dress practically from babyhood.
Case in point: girls shorts. They are made and cut shorter throughout a girl's life. Clearly that 18 month old is not making a choice of her own. Horrifyingly, I also discovered a couple of years ago that while boys and girls at this age are generally similar in size, girls clothes are based on smaller waists... so as parents and young girls we're already agonising because our girls are in clothes that are too many sizes up. Age 3, DD was quite chunky admittedly. I bought her shorts by eye... they turned out to be size 10. They were, admittedly, baggy and loose and long but she wore them (v v good elasticised waist). She STILL wears them, and she's 7 now. The remain her longest shorts....
Similarly, she spotted a pair of PJs she had to have the other day - they glow in the dark
. They are, as it turns out, boy PJs (blue, with sea animals on - so clearly boy). They are her absolute favourite short sleeve pyjamas because the shorts are long enough they don't go up her butt crack or between her labia....
At DS' toddler sports group in the middle of winter, I looked up one day and clocked that all the boys were wearing baggy trackies (DS' were lined, I'm guessing the others' were too). The girls were all wearing leggings..... There was NOTHING sexualised about any of the girls, but I had to ask myself what we were telling this 3 year old girls about dressing.