Its obvious that certain people should not be having children, if you cant afford them don't have them. Change your circumstances to enable you to have kids.
There are situations where relationships break down and some mothers end up single which is a bit different, you cant foresee every eventuality.
Nonsense.
There are a ton of utterly essential jobs that only pay minimum wage and yet modern society relies on them to function.
What are you essentially saying is "only the wealthy should have kids".
Not everyone can "change their circumstances", There will always be those in minimum wage jobs doing "essential work". Why should they not be able to start a family too?
The issue is that "minimum wage" is not enough to cover the cost of having kids, not that people on minimum wage shouldn't have them.