I’m not sure there will be many children. Especially if there are sex robots. People already prefer the company of machines and they’re shaped like little index cards. Imagine when they’re shaped like humans but not as difficult.
But look on the bright side: this is real vertical integration, people! Just imagine a future in which the same company can sell you a) a robot to teach you at school; b) a robot to compensate for the fact that you never learned to make friends at school; and c) a robot to gratify you because you’re lonely, alienated and your job just got automated out of existence!