1. A woman forced into motherhood by a partner who refuses to allow her to terminate the pregnancy
2. A forced mother (rape, abandonment) who was unable to opt for termination for whatever reason
3. A stay at home mother who thinks its too much hard work (as compared to...? We never find out what their expectations are)
4. A resentful mother with the wrong or unsupportive partner and whose anger and resentment towards said partner may now be directed at everything related to them (e.g. children)
5. Women who had children "too early" and feel resentful missing out on youthful freedom
6. Women who miss their youthful freedom
Etc. Some of these are quite understandable, some appear to be naivete, and some appear to be pure laziness or a lack of responsibility (i.e. deficiencies in moral character).