Children are 5th house / sun.

Fourth house--home (house, property, etc), family (lineage), mother (some say father). Keep in mind these things, the early family home and such, influence the root of our emotional body, though that's ruled by the moon.

I think it was Ernst Wilhelm who said that NN/Rahu in the fourth is about emotional intelligence and honesty--parsing secondary emotions from primary emotions. The person with this placement will encounter relationships (not just romantic) that challenge them to do this throughout their lifetime.

Fifth house--pleasure, sex, children, fun, hobbies.

I guess the thought I've been having lately about wanting kids has nothing to do with my north node placement then. That's partially why I was curious if kids had to do with 4th as well as the 5th house since 4th house has to do with family.

My 5th house is empty but I do have Pisces ruling it.

Jupiter rules Pisces, and from what I remember, your Jupiter is ruled by the Moon—motherhood. You’ve either recently gone through, or are going to go through, a Jupiter opposition to your natal Jupiter, so it makes sense you’re reflecting on lunar themes, and the Cancer/Cap axis. Couple that with your Saturn Return—maturity, adulthood, goals, big life decisions, etc. Right time (Saturn) to be thinking about the things you are. 

This post Elsa just wrote is applicable to you:

https://elsaelsa.com/astrology/how-will-the-2020-capricorn-stellium-affect-me/

The fourth rules the home and the fifth, children, because we make a nest, and then have kids (not always, of course, but that’s the idea behind that particular stage of evolution).

Thanks for the input on that, Buendia.

I suppose it would affect my 4th house north node as Cancer rules the 4th house, I have Jupiter in Cancer, and Jupiter also traditionally rules Pisces which is my 5th house.