I will jump in on the whole boy/ diaper situation. My son turned 3 at the end of May. We have been trying to get him potty trained but he is stubborn. In general, boys are more difficult to train than girls. Some of my friends, had their boys trained in no time but other friends have told me their sons took awhile. Sometimes it is stubbornness, sometimes a complete lack of interest and it could be a sensory issue too. My pediatrician told me to use whatever bribery we can. We are now using candy and toys. I will be adding a sticker chart to the mix soon. It all depends. If her child is now 4 and still in diapers them there might be a medical issue or they are babying the boy too much. Between 3 and 4 is a good time to train a boy.