Mel, my DS is nearly TT - I say nearly because we can go 2 days without an accident, then he gets distracted and we have one. And he will keep poo in his pants for a while without being bothered by it too. It amazes me, as he hates having dirty hands or anything, but doesn't seem to mind that. Maybe they get used to it from being in nappies. Anyway, you are doing a great job, so don't feel bad about the odd accident. I would talk to your SDD and tell her that even if she has a nappy on she should still keep it dry and use the toilet. That way if she gets put back in them, she can show her mum what she can do. GL.