I might move into a caravan

I should have known that the whole '3rd Child' conversation wasn't just going to disappear into the memory banks and never resurface. I had hoped, I guess, that Philippa's comments on Sunday would be left with me and she'd let me ponder it and mull it over, but I forgot that my wife just doesn't operate that way. She gets an idea in her head and it stays at the forefront of everything and she expects it to be the same for me. So, as soon as I walked in tonight it was raised as a topic of discussion again.
"Did you get a chance to think much about what we talked about yesterday?"
"Not really, love. In between staff rotas, stock orders, management meetings and budgeting conference calls I barely had time to think about breathing, much less plans for our homelife."
It led to a strange evening, to say the least. Philippa's weekend visit to her friend seems to have cemented this perfect scenario in her mind in which our family unit is completed by a daughter at the earliest possible convenience. I pointed out that we are currently both exhausted by the two offspring we already have, and that there isn't really available space in this home for another child, and that we would have to buy a bigger vehicle - again - and that she is now about to start trying to get clients as a massage practitioner while also getting used to being back at work, and all manner of other sensible reasons why not, and she just batted them all back at me like a defensive cricketer in complete control of the crease.
I feel exhausted.
She is just so good at taking charge of these exchanges and making me feel like I'm making ridiculous points and generating embarrassing excuses. And yes - I get the point that I know what it's like to have children the same sex as me, and she doesn't, and that it might be nice for her to experience that, and I get the point that it might be good for our sons to have a female sibling so they can learn what it's like to be around girls and that would lead to them having better relationships with women in the future (any kind of relationships I mean, by the way, not just romantic ones) and I get the point that if we did it sooner rather than later Philippa could still have a career once no.3 is old enough. I get all that, but still...
Why would we bring another child into this rapidly-dying environment that already has far too many inhabitants for them all to survive successfully? Why would we put ourselves through another long spell of pregnancy-related anxiety, only to have it followed by another long spell of sleeplessness, expense and can-we-keep-this-child-alive fretting? Why would we add another young 'un into an already complicated mix of personalities that will undoubtedly cause friction, conflict and awkwardness in their teenage years and early adulthood? Why?
For the love of God, Philippa, WHY???

RC 30-1-24