what are you doing before nap? if it's lunch, how much does she drink? and do you have her go potty before bed? I would also require a pullup for nap, if she keeps it fry thru nap then she earns a sticker. IMO 2.5 is a typical age for starting or even nearing the end of training especially for a girl, BUT even when a child is trained or near the end of training it is still up to the adults to make sure they go every so often, the child does not want to stop play to go potty and are always willing to push the peepees and poops to the limit, having lots of accidents. Until I am sure a child is completely trained I will use diaper or pull up for nap time only, you can't blaim a child for going potty when they are asleep. good luck!