I know a mother who lost her precious daughter to cancer about two years ago. The whole family was devastated, which goes without saying. However, the mother had to keep life going for the rest of her family, even through her grief. I remember her saying that during the day she just would tell herself that her daughter was at a friend's house playing. Then, she was able to function. But, at night, without the daily distractions, reality would hit her hard.
I wonder about Casey in this case. I wonder if her mental state allows her to tell herself that Caylee is with the Nanny and then she is really able to act normal, go to clubs, etc. I bet the days of no contact with friends and family may be starting to wear on Casey. Also, I would expect the nights in her jail cell are difficult. I hope she cracks soon!