O (2.5) has been day trained for a few months now. She's in underwear all day, including nap. She was doing great, hardly any accidents, but the last month or so she's been having pee accidents several times per week. Almost always it's when we've waited too long to have her go, so we take full responsibility. However, a lot of the time when we do want her to go she refuses. What are your tricks for convincing a strong willed toddler that she does, in fact, need to sit on the potty every hour or two? I don't want to turn this into a power struggle, and I don't think we can physically force her to pee, and even when we eventually win, she's successfully engaged us in a crazy power struggle to get to that point. Any clever tricks we haven't thought of?