Clothing maketh adolescents with low self-esteem and perverted self perception?

So, I'd like to pick a few brains on this one, as I'm not sure about anything. Clothing is not my thing. Until recently, I was in the "wear whatever you want"-corner. The more I think about values and social structures, this particular subject is becoming blurry to me, not at all black and white anymore. And it's getting worse being a full time father now (and I thought I had everything figured out...). Maybe some of you can help with input towards my arguments.

A mixed case

Lily is frequently getting new and used clothes (especially from her mom & family), and some of them are not something I would pick for a child. Quite a few are actually things that I stash away immediately - explaining, of course, to Lily, that they're adults clothes and not for children. For example, belly free tops and shirts, trousers that sit low on the waist, shirts with a cleavage - not that there's anything to see, Lily is 6 years old. But it's a matter of principle, which I will try to explain now.

I have two main concerns:

1. Sexualization

I know the argument about empowerment, but for me, it's still more sexualization than liberation. Especially when it's a child. Children play hard, get dirty, fall, scratch and all that - they don't need pretty clothes, they need practical clothes. They do have a desire to be pretty sometimes, but pretty, not sexy. The hyper-sexualized environment we're in with publicity blasting from all sides is already enough, I should not enforce that, but rather try to mitigate the effects of it.

2. Adultilization

That's the case of a friend of mine. Her daughter is 14 years old now, and playing adult way more than to be expected at that age. Since my friend had taken her daughter to a lot of events with her (adult) friends from early on, the psychologist said that the high exposure to adult-life and low exposure to child-life (the kid didn't have many play-dates or things like that) caused the unconscious wish to become an adult a lot earlier, copying as well clothing styles that I myself consider inappropriate for the age, as they lead to older men hitting on her - which the girl, in her childish innocence, doesn't really understand. On top, it also reinforced a kind of inferiority complex, as she always compared herself to adult women on one hand, and magazine "women" on the other hand. Her self-perception is totally out of line, as is her self-esteem.

Put my clothing where my mouth is

I'm live what I preach. Clothes have to be practical. Even when I want to dress up like on the weekend, the clothing serves exactly that purpose, they're practical for that. I do know how to dress for special events, too, how to behave, how to pretend - keyword manners. I'm a little extreme, I admit - almost all of my socks have holes in them, I just turn them around and use them upside down until they have holes on both sides. That comes from contact with scarcity trauma. As mentioned, I do have nice clothes as well, but of those I take extra care.

I know that neither of the girls is wanting the result that they get. But I try to preserve at least my child's innocence as much as I can. I don't want her to compare herself to women, I wish she wouldn't even compare herself to children - but that's inevitable. At least it would be the same age, and considering the children she hangs out with, I'm not very concerned for now.

Instead of empowering her to do whatever she wants whenever she wants, I would like her to be empowered enough to not care about superficial things like looks and clothing. Again, inevitable, but shouldn't I at least try to influence that a little?

What would you do?

It would be great to get some feedback from the community. You don't have to be a parent to comment and have an opinion, but please, put in some arguments why you would be in favor or against girls and adolescents dressing themselves however they want. Doesn't have to be an essay, but maybe your main argument, or two. Thank you for your help!

Some bullet points to consider (I did not work out all the arguments here in this post):

Empowerment
Culture
Machismo (We live in Ecuador)
Liberty
Expression of self
Rules & Limits
Self-Esteem
Sexualization
Sex Crimes