Ok, just to reiterate: My friend did not tell the girl she HAD to change she told her that she was uncomfortable taking her to a public place like the mall in the outfit, she gave her the choice between staying in the outfit and staying home or changing and going to the mall. She tried her best NOT to embarrass the child. She said her exact words to the irl were along the line of "your top and shorts are a little short for my taste" she said she even made a joke about being an "old lady." She also said she hasn't had any issue witht he child's behavior (and she is over a lot, because they have a swimming pool)
I agree that style is subjective, but I have to agree that, in this case, the person is a minor, and is the responsibility of someone else. The reason that they did not go to the mall was that my friends OWN daughter decided to act like a fool, the friend agreed to change.
She also said that the mother was not home, and often is not. (which may explain a lot)
As some other posters had said, I am not sure how I would feel if another mother/family said my child was not dressed appropriately. I think I, too, might be offended or angered, feeling my judgement as a parent had been questioned. But, I think, as adults, we (I hope) we have the judgement to asses the situation, and dress appropriately. A child may not have this judgement. What might be appropriate for the pool may not be appropriate at a restaurant, or at grandma's. The shorts and top that are appropriate for grandma's may not be appropriate for visiting more conservative Islamic friends.
While I wholeheartedly agree that how a person is dressed will NOT cause them to be assaulted, I think that young girls dressing "older" or provocatively may lead them into situations they may not have the maturity to handle.