My point is that there may be better times, but there may not. If the woman sees her life changing in a significant way in the future — for instance, if she is in college and believes that she will get a better job in a few years, then waiting is definitely wise. However, many people who are poor are poor their entire lives. If the woman sees no significant prospects for change, or if she is reaching the end of her fertility, it’s not an irrational decision for her to go ahead and get pregnant if she really wants a child (or to have and raise the child if she finds herself pregnant).
It’s also worth noting that the “appropriate quality of life” is a very relative measurement. If you grew up poor (or in a country where general quality of life is much lower than it is in the United States), then you many consider going hungry only on occasion a decent enough quality of life. You lived through hunger and you figure your child can, too. On the other hand, if you grew up wealthy but lost your fortune, you may think it impossible to raise a child adequately on a $100,000/ year salary. Some people would be aghast that the single woman working at McDonald’s might even consider having a child. Others would say that everyone in the neighborhood is in a similar position, as were their parents and grandparents before them, so why should she wait?
It’s very difficult to enforce (through social pressure or otherwise) the notion that women or couples should wait to have a baby until the appropriate time when there is and can be no real consensus on what “appropriate” means and when those who really want to enforce the standard are generally of a higher class than those they believe to violate the standard and those who supposedly violate the standard generally view those who created the standard as busybodies who have unrealistic expectations about life (or at least the lives of those they criticize).