Fair enough, but the reasons why OP never experienced a smooth pregnancy were not due to health issues, they were due to bereavement and domestic abuse.
I do agree that OP needs to be clear that having a child cannot be solely about the pregnancy and birth experience - after the baby's born there's another 18 years at least of raising them, and a lifetime of being their parent. She has to want that for this to work. But OP has three kids so I think it's a safe assumption that she knows how much work is needed to raise a child.
People always say this when someone wants more than two kids - if you have a third will you want a fourth, a fifth, etc. But is having five children something we all hope for, really ? while we all place the limit at different places, most of us know when we're done. Personally, I tried hard to convince myself I was okay with two, but I wasn't. And when I had my third I was very clear that I would never want a fourth, and that feeling has only solidified with time. So I don't think most people just want an infinite number of kids.
If I was OP, by the way, I wouldn't go for it. She's spent 21 years raising three children, I don't know where she finds the energy and motivation to want a fourth ! But the fact is that she does, and assuming she's aware of the risks and the costs, I can see no objective reason why she shouldn't, aside from very personal preferences and life experiences.