Mary Maloney is the quintessential doting wife. She anticipates her husband's every conceivable notion, desire, and or need. Take a look at the first paragraph.
The room was warm and clean, the curtains drawn, the two table lamps alight-hers and the one by the empty chair opposite. On the sideboard behind her, two tall glasses, soda water, whiskey. Fresh ice cubes in the Thermos bucket.
Notice that she has the lighting perfectly set for where Patrick is going to sit, and she even has his drinks ready and waiting to be poured. Whatever need of his that she has not anticipated, she is willing to immediately execute once she knows what he wants or needs. Patrick doesn't even have to remove his own coat. She takes it from him, and she hangs it in the closet. Patrick's personal comfort is paramount to her, and she loves sitting down with him and knowing that her actions help to make him happier.
She loved to luxuriate in the presence of this man, and to feel-almost as a sunbather feels the sun-that warm 25 male glow that came out of him to her when they were alone together.
This incredible portrayal of her is what makes her eventual killing of Patrick such a shock to readers.