Marie doesn't really contribute to the plot besides buying the wrong chips and giving handies
her only contribution to the story is to allow housewives to have something to relate to. when hank was going through therapy and he was competing with the trainer to finish his workouts, that awkward high five marie tries to impose on the men is something women relate to. but as far as plot points, her getting caught stealing was her emotional breakdown which led her to ask the police to include her husband to ease their family life. if it wasnt for her stealing, there would be no reason for hank to ever look into the case after he was shot.