I feel like I've already answered my own question but here goes! Sorry for TMI.
I have two wonderful kids (4 and 6). When my youngest was born, I was SURE I would have another. But we had a hard couple of years after she was born -- financial struggles, trouble at work, my mother who was diagnosed with a terminal illness and passed away. DD1 also had a very worrying speech delay and I spent a lot of time taking her to speech therapy and working on her speech.
Many of the difficult things have changed. I got a much better job, my daughter is now caught up in speech (and now actually ahead of peers academically reads very well, e.g.), and the pain of my mother passing away so quickly has eased. The one factor that always stopped us was finances we were totally fine, but had little leftover and it was always a worry. Our joke was that if we ever won the lottery, we would have another kid!
Well we kind of have won the lottery in the role of a very unexpected inheritance from a distant relative. (I know it sounds like a movie.) It is a life-altering sum of money and would allow us financially to buy a bigger house, fund college for our kids, hire a bit of help, save for retirement, etc.
So it seems like a no-brainer to go for it. But these threads have really made me realize how risky a kid at my age (40 would be 41 when kid was born assuming no fertility issues.) As one parent with a severely autistic third child wrote why risk it?
That said, I know other mothers my age who now have little babies and I'm so jealous of them, and that feels right but my fears over having a kid with severe special needs is what is now keeping me back. I could have handled it for my first or second kid but third, I would massively struggle and feel really guilty for my first two kids.
I think this fear is compounded by the fact that DD1 had been so behind and I was on the SEN threads here a lot (which were lifesaving) and I saw how much other families struggled with much more severe limitations. It gave me a glimpse as to the what-ifs . . .
DH is inclined to stick with 2 now but would be absolutely up for 3 if it's what I wanted.
Anyway, it's pure head/heart -- head says "don't risk it" heart says "go on, it's what you want." Right now my head is winning and it makes me so sad. Any thoughts on if I'm being unreasonable?