I'm not sure if Alan Ball did his homework and the scene referenced actually occurred on p. 67 in any edition of the novel.  (I read Georgeanne's line as character color--that it's such a fantasy for her that she has a photographic memory of the specific page in The Godfather, whether that's the real page or not.)  But what is very apparent from the context is that Georgeanne is referencing Sonny's dalliance with his sister's maid of honor at her wedding.  In the novel, the bridesmaid (Lucy Mancini) is a more substantial supporting character than in the film.  Georgeanne hopes that Tommy would "pull a Sonny" and ravish her while the reception's going on and her husband's somewhere else.  That's always the way I interpreted the lines, at least.