Mary Maloney, in Lamb to the Slaughter," experiences both internal and external conflicts. Write a detailed paragraph using evidence from...

I would say that Mary Maloney faces three of those four types of conflict.  I would also like to point out that most of those listed conflict types are external conflict types.  

Mary endures a man vs. man conflict against her husband, Patrick.  He tells her that he is leaving her.  Mary experiences a bit of a psychotic break, and she ends her conflict with Patrick by clubbing him across the skull with a leg of lamb.  

The man vs. man conflict continues once Mary has the police officers in her house.  They are trying to figure out what happened to Patrick, and Mary is trying to stop them.  I'd say that Mary is quite successful in this endeavor too.  She manages to convince the officers to eat the murder weapon.  

The man vs. circumstance conflict occurs throughout the story, but it is most evident when Patrick tells Mary that he is leaving her. Patrick has forced Mary into a situation that she is not capable of handling.  She operates in a daze until Patrick's cold, dead head hits the floor.  

The violence of the crash, the noise, the small table overturning, helped bring her out of he shock. She came out slowly, feeling cold and surprised, and she stood for a while blinking at the body, still holding the ridiculous piece of meat tight with both hands.  

You might say that Mary continues to struggle with her circumstances until the end of the story.  I would agree with you, but once Patrick is dead, Mary begins actively controlling the circumstances; however,  I like thinking that characters have zero control over the circumstances in a man vs. circumstance conflict.  That happens to Mary the moment Patrick walks in the door until he finishes telling her his awful news.  He is the one actively guiding the situation, and Mary is only capable of reacting.    

Mary's internal conflict is mainly focused on her avoiding jail for the sake of her baby.  She is pregnant, and she is the wife of a cop.  She is perfectly willing to take the punishment, but she doesn't know what will happen to her child.  She struggles with what to do.  Turn herself in or get away with murder?  She determines to cover the murder up in order to keep her unborn child safe.

It was extraordinary, now, how clear her mind became all of a sudden. She began thinking very fast. As the wife of a detective, she knew quite well what the penalty would be. That was fine. It made no difference to her. In fact, it would be a relief. On the other hand, what about the child? What were the laws about murderers with unborn children? Did they kill then both-mother and child? Or did they wait until the tenth month? What did they do?

Mary Maloney didn’t know. And she certainly wasn’t prepared to take a chance.