If she needed a reminder of how different life was from her mother's favorite happily-ever-after movies, Dinah Dewberry got one on her fortieth birthday. That's when she found the black 42-double-D bra in her husband's pants pocket. Dinah was barely a B. And as Dinah raged about the other woman, her estranged sister, Dottie, arrived on her doorstep. Dottie was pregnant, and had a favor to ask-…