My DD (13) went shopping at the weekend, and has bought some absolutely TINY knickers (I've just found them in the wash). They are the most miniscule thongs imaginable. You could literally fit them in a Kinder Egg capsule, with room to spare.
I'm torn between respecting her underwear autonomy (and guessing that it might be a brief (arf!) experimentation, and putting my foot down and saying she needs to wear something more age appropriate (which IMO means non-thong, and made of something comfier than nylon).
What's the MN verdict on young teenage undies?