realistically the solution is going to be artificial wombs, which are already being tested in Japan and the US. They'll get them in the door initially for women who can't have kids naturally or homosexual couples, but eventually it will be normalized or governments will just create as many test tube kids as needed

only other alternative is a massive propaganda campaign to raise the social value of being a mother to how it used to be, where motherhood was socially seen as being far higher status than having a job for women. That's the current problem, years of women being told that "freedom" and having a job is way better than having kids. It's really not a money/stability issue, because the poorest people in Western countries have the most kids