PROMISES With her three children, beautiful home, and loving husband, Margaret Crane is a woman others would envy.  Adam's job has cushioned them nicely over the years, and it should be a time of contentment, rewards, of new challenges together.  But lately Adam has been working too late, too hard, at the office. Margaret is sure it's just the rumored takeover of his company--until she meets Randi, The Other Woman...Meanwhile, Nina, the orphaned cousin the Cranes raised as their own daughter, is reveling in New York.  She thinks she's found Mr. Right in Keith, a brilliant investment banker.  But Keith has a secret he has not shared with Nina.  All he asks for is time...and patience.  And as Nina clings to stolen weekends with Keith, Margaret plays dutiful wife, trying to ignore warning signs of her own failing marriage.  A rift has developed between the two women who have loved each other as mother, daughter, friends.  Keith is not welcome in Margaret's home.  And Nina herself is the other woman...