They weren't babies then, but toddlers, babies can't squat, they can't stand up.
I've come across this before it's called "elimination communication" ( http://en.wikipedia.org/wiki/Elimination_communication ).
The story at the end is interesting - our first could tell us from about 8 months if he wanted to use the toilet by using sign language. He couldn't at that stage sit on the thing without being held up.
It doesn't appear to be useful from birth, so not "diaper free" unless you want sticky black neonatal feces on your stuff. Crapping babies in an open bottomed papoose in a field are one thing, even in a soil floored hut (just swap the soil), in a carpeted house another.
Also, crotchless pants (as it's North American I assume they mean trousers), don't they freeze their bits off?
Lastly can't find anything about her own family, all the bios just have info about her background in Chinese medicine.
Edit: One son, http://www.flickr.com/photos/27779597@N04/3774983613 plus this is interesting http://www.spinachandhoney.com/search/label/Diaper%20Free
