It seems to me that with natural selection, women who still choose to have children today despite having an education, employment, and all of the other factors that seem to harm the birth rate, their children will likely have as many children as they did or more, even with the same gift of modernity their parents had, and this issue will stabilize or we’ll resume population growth in 50-100 years.

Not sure why you're being down voted. Maybe because it's distasteful? Doesn't make it false. We are in a period of adapting to the introduction of birth control and modern conveniences. People with higher reproductive drive will reproduce and pass on the trait. People with lower reproductive drive wont. This isn't a judgement, just reality.