I know that she's ready, both mentally and physically. She meets all the requirements for potty-training, and more.But at 3 years and 6 months old, my Aerin is still in diapers.It is not for lack of trying. Books and videos. Pretty underwear she chose herself. Setting schedules. Going without diapers or underwear. Going full-on nude. Having her older sister (whom she shadows and copies all the time) demonstrate. Bribing. Begging. If you've seen it or read it online, I guarantee I've given it a go.By this point, I know that it's just a battle of wills. Because on the few occasions I have made her sit on the toilet — for up to FIVE hours — she still refused to go. And as soon as...