Yes, the part where having unrealistic expectations of a partner can lead the end of a relationship is coherent, if obvious, The part where the women is left raising a child alone is neither.
It should also be obvious that maintaining two households is significantly more expensive than one. So excepting the cases where both parties reconstitute a household, these folks are on average poorer than their married counterparts in societies with minimal divorce. Further, the rate of failure to pay full child support in the US is high, like over 50%.