[2020] Does anyone have information on keeping track of villager family trees?

I thought it would be fun to keep track of a single family tree throughout a play-through, but I realized there's no way to really tell whose kid belongs to who, other than their surnames. If you have several families sharing a surname (because they're related), then it can be difficult to tell which villager pair actually produced the child.

One solution I thought of just now is adding a number to the end of each villager pair's last name, so when a child of theirs is born it should have that name as well, but I haven't tried it yet. I assume it will work though.

But still, has anyone else tried this or something similar? I couldn't find any discussions about this, so I'm curious! Thoughts?