Mackenzie Foy

Murph (young): "Why did you and mom name me after something that's bad?"
Cooper: "Well, we didn't."
Murph (young): "Murphy's law?"
Cooper: "Murphy's law doesn't mean that something bad will happen. It means that whatever can happen, will happen. And that sounded just fine to us."

Cooper: "Murph. You have to talk to me, Murph. I have to fix this, before I go."
Murph (young): "I'll keep it broken so you have to stay."

"There's a lady in a dirty nightgown that I see in my dreams. She's standing in front of my mom's bed."