The singer-songwriter received a nod for her debut album Alas I Cannot Swim in 2008 and has also been recognised for this year's follow-up I Speak Because I Can.
Talking about her nominations, Marling told The Observer: "It's made me feel very happy. And scared. It's made me feel very alive, I guess.
"I don't really understand awards... And nice for my parents to have something to show... or whatever. Everyone gets given a little statue to say that they were nominated and I gave that straight to my parents so they'll have another one."
Of losing out two years ago to Elbow, Marling said: "When they were about to announce it I did think I won't be able to stand up if they say my name.
"In retrospect, it was probably pretty good that I didn't [win], because my career would have taken a very different turn."
Asked about competing with her boyfriend Marcus Mumford, whose band Mumford & Sons have been nominated for their debut Sigh No More, she added: "I think it will be really funny. Not funny. You know... It's really bizarre. I just can't believe it."