What happens if you take her to the toilet when she brings you a nappy?

If she know when she needs to go that's a good sign she is physically ready, but maybe not quite emotionally if she is insisting on wearing a nappy to do it. I would just go with the flow. Keep offering the toilet but if she says no then pop her in a nappy. It won't last forever and it's much easier to be relaxed about it and slowly make progress than both be stressed and get no where iykwim?