I am more tired with 2 children if I stay at home, than when I'm at work.
Probably because of the rut, every day is the same. When I work, I communicate with my colleagues, I feel useful, and I can honestly be a better mom.
My kids were at home from kindergarten more than a month in December/January, and we were all a bit crazy (they are in kindergarten from approximately 8 until 3).
So I understand her. And maybe she got baby blues, PPD or something. This is all hormones related, does not have to be because of a bad marriage