Cheap child care. Not sure how tech is going to help with that besides providing funding. Maybe match up parents for collective kid-watching, at least occasionally. Related to that, find or provide jobs that are flexible and can work around parent's schedules but still pay well.

Distribute information that having kids early and getting (back) into a career later in life works fine.

Collect knowledge and how-to information from reputable sources and make it accessible to everyone. That way, people don't have to have a pre-developed social network of parents to ask questions of. They won't feel like they have to figure everything out from scratch.

Minor point: single-parent families are getting more common. Normalize it and avoid calling them "broken homes" or otherwise being negative about it.

Well religions increase population. Some religion like Mormonism (lds) are more explicit about the population increasing.