How to decide between two families which one you belong to when they have alot of surnames in common

Question

I am a little confused I have been building a tree for both a man with the last name kunde  as is his father's last name but his mother was adopted  and a man who's mothers maiden name is sumpter but doesn't for sure know who his dad is may be a last name of ladden? Then we have the mother whose mother and father are a fuller and yarolem  the sumpter last name and the kunde last name both share a lot of common surnames but I'm not quite sure if they connect anywhere yet or not but I have a list of matches from ftdna and my heritage and other sites also but I have matched a few people in the kunde family but there are  also a few that match the surnames in the sumpter family how can I find out which family this little girl belongs to

Answer 1

Try looking at the dates when born. My rule of thumb is look at the date and go back say 20 years for the next one. It should be in the ballpark.

Lilly Smith G2g-6