I would not bother with trainer pants, especially if money is tight. With children you have to be prepared for spillages anyway. If your child can tell you when she is about to do a wee then she is ready, poos are always more difficult for them but conquer the wees first. Its a good idea when they are toilet training to carry a potty round with you in a bag, in the car or push chair, as you usually dont get much notice to start with, and obviously have spare clothes at all times!!!