I don’t think you can really vet anyone with 100% certainty.
Someone might have no kids but might end up taking leave of absence for sick relative or for their own health. But even when it comes to kids. I have a coworker who unexpectedly had to take 3 young children in due to tragic death in the family. It completely changed everything she ever planned to do. So even if one never wants to have kids, one might end up with them.
It’s all very frustrating but I just don’t know how it could be 100% prevented