The 24-year-old played Winslet's daughter in the hit US drama series and she had a full-frontal nudity scene.
Speaking on the Chelsea Lately show, she was asked if Winslet helped her prepare for the scene.
She said: 'She did, I was gonna chicken out, you know, and she pulled me aside and Kate's done everything, you know, so you look like a p**sy.
'If you don't do it, she basically dares you. She's like: [In a British accent] 'I've done it all, alright, I've peed on camera and then had to make out with Harvey Keitel.'
And I was like: 'Wow yeah that trumps my whole nude scene, I'm going to have to do this.''