If you're looking for a smart, irreverent and witty summer read about women of a certain age, Elinor Lipman's The View from Penthouse B should fit the bill.   When Gwen's beloved husband dies, Margot, her recently divorced older sister, invites Gwen to move into her luxurious West Village apartment.   While somewhat of an "odd" couple, the two are bound by sisterly love as they seek to reinvent themselves in often hilarious and sometimes touching ways.