For me, the biggest factor here would be a husband who works away a lot. I would never have had a first let alone a second child had this been the case- my husband works from from home and is an extremely hands on parent, and I know I would not have coped well with parenting without this.
However, plenty of women do cope and so it’s entirely down to your own personality and your coping mechanisms.
I would also be inclined to think about what happens if you had a second child with health concerns or high needs relating to SEN. Clearly, it’s impossible to know what life would be like but it’s always a risk, especially when the parent is older, and I would again need good support around me to manage.