if shes just started nursery or school then shes bound to be feelind a little scared - just like we would with a new job - thats possibly the cause of it!
my mums friend has got a son whos 12 and he wets the bed - this is the result of some major family problems that have really affected him,he cant have/go sleepovers or anything cuz of it.
small little things can worry kids the way they do us,or it could just be a faze - i was only readind an article lastnight for a friend that no matter how early u potty train ur child,u will alaways end up at the same level everyone else is at at some point - il see if i can find the link again...
succesful potty training for girls:
http://www.babycentre.co.uk/toddler/pottytraining/forgirls/
potty training: was my child ready?
http://www.babycentre.co.uk/toddler/pottytraining/whenchildready/