Mrs. Perfect / Jane Porter.

Enhanced descriptions from Syndetics:

As a young California girl growing up in a blue collar neighborhood, Taylor Young dreamed of being popular, beautiful, and acquiring a wardrobe to die for. Not to mention marrying a handsome, successful man and living happily ever after in a gorgeous house with three wonderful children. Now, at 36, Taylor has reached the pinnacle of her dreams, but is it all about to unravel?

As the new school year approaches, Taylor prepares herself for playing the perfect alpha mom: organizing class activities, fund-raising, and chairing the school auction. But the horror! Her archrival, bohemian mom Marta Zinsser, is named Head Room Mom of Taylor's daughter's fifth grade class. As tensions rise at committee meetings and school activities, the two rivals seem to be destined for a final confrontation. But as Taylor plans her next move, she is floored by a more serious blow at home-her husband has been secretly unemployed for the past six months. With her posh lifestyle crumbling, Taylor struggles to maintain her alpha image -- but could Marta, who cares little about appearances, be her only true friend?