I remember having these same thoughts. Oh the irony:
It was at my second job out of college I worked with a woman who was 42, child-free, single and living alone. And I remember it being almost a revelation to me that “Wow, she didn’t have kids. Like, she’s past that point in her life now that’s even an option.”
I remember in a weird way viewing her as slightly alien because she was the first adult woman that I could recall who was “40” and didn’t have a husband and kids. It felt like “Oh I want to avoid that fate.” In fact I may have even told friends “I don’t want to be in her situation when I get to that age.”
While I now know many child-free, single adult women, my friends who are close to my age are all paired off, and many have started having kids. None of my closest female friends who are older than 35 are both single and child-free.
This 42-year-old coworker I met when I was 24 was really the first time I understood the idea that not everyone was married and not everyone would have kids. But it was not the time that I realized that this state of being a child-free, single adult women does not necessary mean one has a life of unhappiness. I think I still struggle to realize this fact.