DD will be 3 in January. Initially I imagined we'd potty train this summer gone, but when she was nappyless with chicken pox she just peed everywhere so we guessed the time wasn't right. Then I thought we'd maybe give it a bash this Christmas but... I don't know, my gut says no. She struggles to pull her trousers up and down. We try the potty occasionally and she managed one pee by accident, but nothing since. She knows what it is for but sits for about 3 seconds and doesn't seem to try to wee (no clenching of the tummy etc). She doesn't poo at regular times. She rarely tells us when her nappy needs changing, though she will now accept that it does need changing when we tell her we are going to do it.
I know nearly 3 isn't late but still, part of me thinks we should try and if I try at Christmas it will be at parents house so it's their carpets which will suffer 
while another part of me just keeps thinking she's now quite ready.
Though pre-school is possibly looming at Easter and I expect they'd prefer her to be potty trained.
So, am I missing something - how are we supposed to know when is a good time to start?