This subject comes up from time to time and causes heated debate.
As a rough generalisation seems to fall into the, "seeing pants is fine don't sexualise my 6 yr old" camp and the "I want my child to feel comfortable to do cartwheels without teasing" camp.
I can understand both viewpoints. If we take the first viewpoint, then obviously little girls are not in anyway responsible for adults feeling uncomfortable about them flashing their pants/genitals. And of course girls clothing should not be policed.
Imo, this is where the difficulty arrises, because our society and many others does police, have expectations of what females wear. Whether it's, wear what you like or wear what I tell you too! So much interest in the female body and what clothes it.
The decision I have made for my 6 yr old, is she wears trousers or shorts depending on weather. Both ok for school. I would really struggle with a school that did not allow females the option of trousers or shorts. When she gets older she will make her own decisions on what to cover her body with (dependent on uniform requirements).
My reasoning on this, comes from the "I want her to be as active as possible" camp. This is usually were posters pile on stating " skirts don't stop my daughters climbing trees and doing cartwheels".
Which may well be true for individual girls.
However there is research that suggests that clothing does have an impact on how active female children are. I am not going to post a link to it, I don't have it to hand. I read it a few years ago pre children, came from Australia, and the results indicated that as female children age, they were more likely to sit around the edges of playgrounds chatting than being active at lunchtime. The type of clothing worn was found to be an active factor in the choices of lunchtime activity. I am guessing other factors are at play as well though.
This had quite an impact on me when I read it. And I have developed a position that children's clothes should be fit for their purpose. Therefore, I want my child to be as active as possible, not held back by clothing or flimsy shoes. Partly this view is formed by my own experience, inactive childhood , followed by adult obesity. And, no I don't blame wearing skirts to school for my adult obesity, but it is one of many factors I am trying to influence to give my daughter a different start in life.
Adults wear clothing for all sorts of different reasons, feeling attractive and attracting a partner being part of that. I don't think that should be part of children's clothing and yes young girls clothing starts to become "adult like" too early.
My DD wants a crop top, my answer so far is " have you seen Paul/james/Ryan wearing a crop top?" There is no reason that a 6 year old needs to show her stomach in order to dance/move around. The Crop top is not serving a functional purpose for a 6 year old.
Young boys clothing does not limit them in anyway from being active and yet young girls are sometimes being given the message that their clothing is not suitable for being active in. This is so wrong. I have decided to circumvent this, by going down the "practical" route.
I know that not everyone shares these opinions and I do not judge other parents for the clothing decisions they make. We are all formed by our own experiences and trying to negotiate parenthood as best we can!