It is hard at that age...im pretty sure DD is already at that stage now when she will fight tooth and nail to pretend she isnt tired!! :sigh:
But i can always tell by her face, her eyes get puffy, but its normally a tad late by that time. If im good i can catch her before then, she just stops listening to me completely. And runs around like a loon! but before that i think she just gets clumsy!
DD is abit older than yours and she is talking pretty well now soo that is helping ALOT!!! Once she actually came and grabed me by the hand and said ''time, come on'' (bed time) or sometimes will lay down on the floor and make a snoring noise! But most the time she will be fighting it and when i ask her 'are you tired' or 'bedtime?' i get a very firm "NO"!! GL