She is the modern mom par excellence — endlessly apologetic, doing her best yet constantly failing, always tapping into a well of love and humor and wisdom even as she’s falling apart. Photo: NBCU Photo Bank/NBCUniversal/Getty Images Catherine O’Hara, who died January 30 in Los Angeles, will be remembered for her capacity to convey enormous feeling with the smallest movement of her face. She could slide from pleasant blankness to overwrought terror in an instant; she could wield immense power