mention the circumstances that led Godfrey to his ulucky marriage.

This marriage, Eliot hints, is a story of "low passion, delusion, and waking from delusion, which needs not be dragged from the privacy of Godfrey's bitter memory." By this we can infer that Godfrey got Molly pregnant, and due to his soft, pensive nature (and maybe because, deep down, Godfrey is actually a decent guy) he was convinced to take Molly for his wife to avoid a scandal on her part-only to risk one in his own town.