One of my sisters had put DNA in to 23 & Me sometime in the past (several years ago, maybe). Over the past week, she has been notified of a person who just recently submitted DNA for testing. It turns out that this person seems to be our half-sibling. There are 5 of us from same parents, all born from 1954 to 1960. The newly identified one seems to be related only to our father and born in 1964. I babysat for this person and two siblings, when I was around 10 or 11. Their family moved away around 1969,...