She didn’t have kids already, but she wanted to have them in the future. I absolutely do not want kids, I even got a vasectomy in my early 20s.

It’s not really an issue you can compromise on as a couple, so it was better to part amicably than pursue something with no future, for both of our sakes.

I find the question weird.

1. Maybe she didn’t have children but wanted them, that also qualifies as non-childfree.
2. Why is inconceivable for you not wanting kids and not wanting to be with someone who does?