The amount of misinformation on this thread is staggering.
they suggest you wait 3 months after an early miscarriage before trying to conceive again
'They' don't. You can try again whenever you feel ready. It's useful to allow at least one cycle for dating purposes.
Regarding spacing children, there's no one right answer. It's dependent on the mother. It's true that physiologically it takes a certain toll; equally that childbirth is not without risks so the more children you have, the more risk you & baby face.
It's also true that breastfeeding acts as a natural limiter.
But for some women, it's genuinely something they & their bodies cope well with. It's not common now.
Those with misconceptions about Ireland - large families were still very common into the 70s. Honestly, people just didn't think much about it. Women often did work outside the home too, that's another myth.
It also not the case they died early due to having lots of children - they may of course had issues in childbirth but in itself it didn't limit their lives.
Of course, today for all sorts of valid reasons, we want to manage our fertility & make choices about our family size based on a variety of factors - personal, physiological, financial, emotional. Not all those choices were available to women before us.