Heh. I haven't watched last night's ep yet. But she was established as Grandma Lois at Lily's bridal shower and hers and Marshall's wedding.

"You need me. You wouldn't be much of a hero without a villain. And you do love being the hero, don't you. The cheering children, the swooning women, you love it so much, it's made you my most reliable accomplice." -- Lex Luthor to Superman, Question Authority, Justice League Unlimited