Quote 1
"Good God!" [Katerina] cried with flashing eyes, "is there no justice upon earth? Whom should you protect if not us orphans?" (5.4.76)
The novel is obsessed with the lack of justice for children, particularly orphans, as is Raskolnikov. This is a sentiment to which we can all relate. So long as children are suffering in the world, it's hard to think of it as a place where fairness and justice have meaning.
Quote 2
[Katerina:] "Mercy on us, can he have drunk it all? There were twelve silver roubles left in the chest!" and in a fury she seized him by the hair and dragged him into the room. (1.3.49)
Many of the violent moments in the novel involve Katerina. Sure, she has a right to be mad about the stolen money, but it's painful to read about her treatment of her husband nonetheless. It's also darkly comic. We are angry with Marmeladov for not being stronger, and we want something to wake him to the reality of it. He himself thinks the hair pulling might help.
Quote 3
[Marmeladov:] "Allow me to ask you another question out of simple curiosity: have you ever spent a night on a hay barge, on the Neva?" (1.2.7)
Marmeladov tells Raskolnikov that his home life is so unbearable that he had to leave and sleep outdoors. It's obvious from what he says that the horror of his home is of his own making. He knows it, too. He just doesn't know how to turn things around.