I don’t mean to sound unkind, but thinking about the two young parents, this prolonged, still unresolved tension can’t be easy on the marriage. I suspect one of the couple wants to try for a second child, while the other parent won’t even hear of such an idea, and feels they may never be ready for more children.
This is where the right elder relative, or priest, rabbi or even family counselor can help sort things out.
There are likely many urgent thoughts each has privately that remain private, and are never voiced or shared.
I found your post gratuitous and unhelpful.