My lab is 41/2 months old. I have been getting up in the middle of the night and early in the morning to take her outside for a potty. In the last week or so, she has been very hard to wake up and even when I pick her up and take her outside she sometimes doesn't go. My question is, is she too young to be able to hold it through the night? I don't mind taking her, but if I don't need to, I won't pass up the chance to sleep through the night.