I found:

• Family Relations, which tests another set of relations,
• Your family tree, which seems to be a (significant) superset of this problem?

lgtm

Should be good now.

Yes, I made a mistake. Working the fix now.

100/100 tests passed.

um... no

(js)

Wow, you were on this fast!
This idea came from this riddle my Dad liked to say when I was a kid. I hadn't seen anything strictly similar to it, but I'd love to check out the other one if you find it.
This is my first kata submition so I'm not quite used to the process. Thanks for trying it out!

We've had a kata with a family tree like this before. Can't find it, but I'm sure it's a published kata. There are also two beta kata's that play with the same idea, but are more challenging. "Cousin marriage: path analysis" and
"The builder of trees"