It took Matilda around 6 months to work out the poo on the toilet. For some of them its a balance issue, they can't hold their balance & poo at the same time. I know Matilda told me she was afraid of falling in, so we started using a seat on the toilet. We tried rewards, smarty jar, praise but nothing would get her onto the toilet to do it. She got nappy rash badly and I told her that she wouldn't get it if she used the toilet & that was it for her. She now sometimes forgets with wee's when she's busy but will never poo anywhere but the toilet.