A.V.
I find that pooping is often well after peeing. This has been many friends' experience with their kids. My DD is better about pee, too, and we keep trying to catch her so she'll poop IN the potty instead of just before we get there.
I think some of it is just that it's another function and harder for them to control. My DD can say, "Pee and poop go in the potty. I should poop in the potty and not in my diaper" but saying and doing are different things. I'd just keep working on it. She'll get there eventually.