I've read on this board of at least 3 DDs who do this, either in the bathroom or their bedroom.
Is this a new thing we're doing now?
When I was a teenager I was so mortified at being menstrual that I hid the fact from my mother for 2 years. I handwashed my own underwear rather than put it in the wash, until she allowed me to use the washing machine (my mother is very thrifty). Obviously this is the other extreme and I had an unhealthy shame of my puberty - blame both parents for that - but I just can't imagine a world where daughters go around proudly leaving their old tammies and STs all over the floor! Clearly it happens a lot though...