So in other words, this is a perfectly reasonable stress. Perhaps it is a shock when a woman sees how childbirth has affected her looks. A mother can feel guilty because she is having problems breastfeeding. When a mother is delivering, she gets a lot of attention. Then, often, it all stops.
Babies just take and take all the time.
And the work can be messy, demeaning and boring. This can be a shock to a new mother. It can be a shock to realise that a new mother is not free anymore to live her own life and that there is now a baby for whom she is totally responsible. Mothers can feel they have sacrificed their freedom. Mothers can suddenly realise how much they now have to rely on others, like their husband or parents.