The pair recently filmed the movie adaptation of 'On the Road' based on the 1957 novel by Jack Kerouac and Amy revealed she was impressed with her young co-star, who plays the character of Marylou, a disaffected drifter.
She said: "She's awesome. I knew she had chops. I've seen her since 'Panic Room.' I thought she was fantastic. I feel like she's grown up onscreen. She was great in 'Into The Wild.' The girl's got some chops."
The story focuses on Sal Paradise - played by Sam Riley - who leaves his aunt's house in New York to go on a road trip across the US to discover humanity in all its forms and understand what America is.
Amy plays a former heroin addict and Viggo Mortensen her lover, who Sal encounters on his trip, and although most of the actress' scenes were filmed with Viggo, she said loved getting to know 'Twilight' star Kristen between takes.
She told MTV News: "We had a lot of time with each other and a lot of play, a lot of freedom. She's just really sweet."
Kirsten Dunst and 'Tron Legacy' actor Garrett Hedland also star in the movie.