They can't consent but it does make sense that it's true, I would genuinely bet that more nudes are being shared between 17-year olds than some freak, as this is common to the point where I feel a very large portion of all existing teens have done it.
It wouldn't be so bad tbh, would avoid all the leaks and regrets that comes with it. In term of awareness, I would say that a late teen is fully aware of his/her actions but might not calculate consequences properly.
That lack of understanding of consequences is how we get a lot of bad and good things. Like Aaron Swartz downloading JSTOR (relevant today because of the Anthropic fine). He tried to make the world better, he wouldn't have done that if he knew what would happen.