Head of the Winner family and the Winner Foundation is Mr. Winner. They have great influential power and is one of the wealthiest families in outer space. They OWN the whole L4 colony and many resource satellites.
father - mr. winner
Being a pacifist, he does not wish to fight OZ. He is the dictator of the L4 colony. He owns many resources and is very rich.
mother - quatrine
She is never seen in the anime series since Quatrine died of child birth. She is assumed to have blond hair since Quatre has blond hair and his sister has honey blond hair. It is curly, tied in a pony tail, and brushed to the left side of her shoulders.
sister - yuria
A doctor that works on the L4 colony. She seems to understand Quatre a lot even though she's never seen him before. She cared for him when he found his way back to the L4 colony.
Quatre has 29 sisters in total. We only know Yuria though. He's the only boy born to the Winner family (and the only one not a test tube baby too >_<). It seems Quatre doesn't really know all his sisters. In the show, it clearly shows Quatre have never met Yuria. Therefore he never knew Yuria was his sister. That's why she sort of played a little trick on Quatre. Yuria didn't tell Quatre that she was his sister until she took him to meet their father.