[TechnoViking]

I don't buy her argument that having a second child 9 YEARS apart from the first one is somehow better for the family (at least that is what you've implied she meant).

It's not like they'll be playing together. It's not like they'll go to school together, or have any friends in common. The result will be a huge amount of time taken away from the activities of a young man while mom is being a single parent of a newborn.

No, this is not about doing what's best for the "family". This is about what is best for her. I think it's kind of selfish actually. IMO she needs to focus on the one she has.