B.O.
Hope you'll listen to a grandmother -- kids' biological needs haven't changed that much since my older daughter was born in 1967!
We tried potty training her when she was just over two years old, and as successful as it was, it was always MY idea to "go." So I told her that she could wear diapers until she decided she wanted to be a big girl. Then I found out I was pregnant and would deliver just before the older daughter's birthday. Shortly after the younger's birth, she decided she could be a big girl now that she's a big sister!
I promise you: she will not walk down the aisle in her wedding wearing diapers!!
Grandma Barb