hmm it's a though one, maybe plan a week so you have plenty of time to think and wash sheets etc and take the plunge. Is she a heavy sleeper?
Make sure she does a wee before bed and leave the bathroom light on for her, explain to her that if she needs to do a wee she needs to get up and go to the loo like she does in the daytime, or to come wake you up or something. I'm sure once you give her a go at it, she may take a couple of weeks to get used to getting up.
Sorry that's all I've got and what we did with our little man.
ETA: I found that if we DID put a pull-up on our boy, he'd wee in it regardless... kind of like, he knew what the pull-ups were for so didn't register to use the toilet and once he realised he had his undies on he was fine and went to the loo by himself
