banker's family 

( to the best of my knowledge, this is a SLANG TERM used to describe a family with ONE son and ONE daughter )

I suppose it refers to this "set" of kids as being the IDEAL...

I've never found any OFFICIAL ( book or internet dictionary ) definition...

Do the people of "Urban Dictionary" ever research NEW and/or ODD bits of language like this?

The banker's family walked along the beach, wondering why it needed to be used in a sentence...

banker's family by Mike Mike Mike RRR 111 October 21, 2006