Lauren is part of Bernard's back story; she is the woman shown speaking to Bernard in "The Stray" and it is implied she was his wife. It doesn't seem likely that she has any physical existence. She is portrayed by Gina Torres.
Lauren has a video call conversation with her ex-husband Bernard. They reminisce over their dead son Charlie, and Bernard tells Lauren that the pain he feels over Charlie is all that he has left of him.
Lauren is seen during Bernard's flashbacks. He remembers their video call, but sees Lauren's face change to Ford's, showing that the call wasn't really with his ex-wife.
Lauren and Bernard used to be married, showing that they care very much about each other.
As of "The Well-Tempered Clavier" it has been proven that she never existed, meaning that her relationship with Bernard never existed.
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