Good luck wrinklytum, I am just coming out of a fairly long potty training time... to begin with I needed alcohol at the end of every day.... a glass of wine or a g&t was my reward for getting through the day.
my tips for what they are worth?....give her a drink 15 mins before sitting her on the potty, try to do it regularly(i.e before/after a meal), if she is resistant then relax for a wee while and then try again. Patience by the bucket load helps and being prepared to let your dd dictate whether she is ready.... might be worth taking her potty shopping too.
Praise for just sitting, even reward if you think it might help....Taking your dd to the loo when you need to go might help too and maybe some PECS/other visual prompts like a potty training book - my ds liked "Who's on the loo?" but I am not sure it actually helped.
(I tried my ds at 3, in the summer, he was showing no signs of being willing!) then again at 4, he was fine for peeing after a few weeks,poo took another 5 months) - it was a very stressful time - not because he was having accidents, but because he was quite agitated and also didn't want to go to the loo, especially public loos with hand driers - I am glad we kept trying and something clicked - though he still needs encouragement to go.
my ds did respond well to incentives - i.e we bought him a Wall. E toy and he really wnated it, that was when he had his first potty success!
for poo the incentive is chocolate coins - it has to be something your dd really loves/wants and only gets/associates with the loo/potty