Wow, this turned out to be such a deep topic.
I put off having kids until I was 35. It was due to my husband not wanting/being ready for kids.(Let me just say he is such a good dad and loves having a child in the house, not that we have one). My LB was born just before my 36th birthday (after 12 years of marriage). My husband said either none or two, so there is another in the planning, even in his mind. My sister has only one child and she blames my sister for not getting another. I don't want that to happen to me.
But, being older and having less energy, I sometimes wonder if I will manage. I honestly feel so drained some days that I can't imagine having to deal with 2. My LB still doesn't sleep through at 14 months, and boy, do I love my sleep!
Even though I can't see how I will cope, I can't wait to try for the second one, as Alexander is such a blessing and really enriches our lives. An as one of 4 children I also know how much fun having a sibling can be.