Question

How do I find out if I'm related to someone if you don't know if they had children? Like Agnes Henderson.

Comments

I guess you have to do the research to find a paper trail between you and Agnes.  If it turns out to be direct, then obviously she did have children, otherwise you could still be connected through one of her siblings.

As an aside, my father, who was an irrepressible practical joker, used to love to ask people:   "Did your mother have any children?"

Answer 1

This probably doesn't answer your question, but using the WikiTree Relationship Finder, I find that Agnes and I are 7th cousins four times removed.

Answer 2

Family Search had a record of her birth and baptism, naming both parents, so her profile is now sourced.

The next steps are more complicated.  There was an Agnes Henderson, the daughter of Alexander Henderson, who married Robert Patie in Edinborough, Scotland.  This may or may not be her husband.

There are many more steps on this journey, but I hope this helps.

Regards, Janine