Originally Posted by Cat Herder:
You should always enforce your own policies. If they are not important enough to have, then don't have them. 
Second, he is pretty old to not be potty trained so I understand the frustration for both of you. How many times per day is he being taken to the potty as part of the daily schedule? Is he behind in other milestones? Has she told you of her plans for preschool attendance, yet?
Every diaper change I ask him if he needs to go potty. So, around 9:30, 11:45, after nap (around 2:30), and before he goes home (5:00). He is wet every time. I don't think he is behind on any milestones. We just had a 3 day weekend last weekend, and I really hoped she would work on it with him. But, instead she sent him to his grandma's house. I don't have an answer for why he would be "100% trained at home" (mom's words) but not trained at all here. He's been with me since he was 6 weeks old.
She has mentioned preschool. She told him that if he goes potty he can go to school every once in a while (it's for 3 hours a day, 2 days a week.)