We are also at odds regarding when her son will be able to wear underwear here. He still pees in his pull ups and does not tell me when he needs to go. Earlier this week, she speaks to her son (again on her knees in front of him - oh hail the mighty one LOL)" maybe this week Mimi will be nice enough to let you wear your underwear" so I just kindly said "sure, as soon as he stops using his pull ups and tells me that he has to go" and I smile.
Give me a break. I'm sure your rule is the same as mine regarding potty issues. Still pees/poops in pants on a regular basis and doesn't tell when they have to go? PULL UPS. End. of. story. There's no way we're going to end up with pee and poop all over our houses!