DD is 2.7 years - been sitting on potty morning and night for a long time, mostly performing. Decided to "go for it" potty training 2 weeks ago - knickers she loved, sticker chart which went down great, choccie buttons for poos etc - she did really well for about 12 days and then total relapse and refuses to sit on potty at all, even at night/morning which she'd done for ages. Got her in Pull ups now as so much mess otherwise but thats expensive and not sure whether to go back to nappies - which I swore we wouldn't do....Any advice? Very frustrated as it had been going so well and we'd left it quite late to start trying as we thought it would then "click" quicker...