Throughout the life of a girl there's hundreds if not thousands of ways they can easily become incontinent. Mean if you go through the ages: -Early childhood >Bladder not really developed enough to be fully continent -Teenager >Start having periods that causes incontinence -Early to middle adult >Pregnancy causes incontinence -Late adult >Menopause, enough said -Old age >You get the idea About the only age group for females that would benefit from potty training are in their late childhood stage and chances are they are a bedwetter. Be far simpler and easier all round if they were never potty trained. I am aware that this would produce logistical problems as there would be too much waste to justify disposables. They would have to be restricted to the young and infirm while the rest of womankind would need to get used to the idea of being in reusable cloth. Still it would solve the problem of trying to cater to their unique feminine problems while providing a solution that does not beat about the bush.