Lamb to the Slaughter

This is how I would defend for Mary Maloney in "Lamb to the Slaughter."

There are many reasons I believe that Mary Maloney isn't the murderer of Patrick, her husband.

First of all, Mary left the house to buy groceries because her husband as usual is tired, and so she wanted to cook dinner for him. Mary went to buy the groceries from Sam, and when she came back her husband died. She had no idea why he died, and it's not her fault. No one witnessed that she killed, or act in a strange way. Sam from the grocery shop can prove that she went shopping, and how she was acting normally, or strangely.

Second reason, even if she did (which she didn't) we shouldn't blame her because her husband was going to leave her, and which kind of dad would ever leave his wife with an unborn child. I for instance would definitely kill my husband (if I had one), how possibly can someone be so cruel and cold hearted. I really don't understand, when someone is having a baby that's the most important part when they need someone to rely, and support them.