No formal training? No problem. Jennifer Lawrence is Hollywood’s fastest-rising star. Already an Oscar nominee at the age of 20, she’s about to star as X-Men: First Class’ blue-skinned shape-changer Mystique…

January 25, 2011: Oscar nomination day. Jennifer Lawrence is glued to the TV, watching, waiting. The Best Supporting Actor shortlist is unveiled: Lawrence’s Winter’s Bone co-star John Hawkes has made the final five.

“I was jumping around and crying,” remembers the actress, “and then my category came up and I really quickly had to be quiet.” And the Best Actress nominees are… Surprise, surprise, Lawrence is among them. “The moment it happened, someone took a picture of me and my family,” she says. “Everybody looks really happy, smiling with their arms in the air, and my face is just like… terror. I look like I’ve just found out I’m being sent off to jail!”

It’s a relief to learn that Jennifer Lawrence can take a dodgy snap with the best of us. So she is human, after all. You could be forgiven for doubting it, given her current cachet. Supernatural talent, supermodel looks, and now a superhero franchise with X-Men: First Class. And still only 20 years old, with no formal training. Which would be annoying, except the Louisville, Kentucky native comes across as less precocious and more like, well, a 20 year old. “The Oscars were great, because I didn’t feel like I had to work,” she says. “This time it was like, ‘Oh my God, Florence And The Machine are playing and I have front-row seats, cool!’”

Still, you get the impression Lawrence didn’t have to dig too deep for the remarkable display of self-possession she offers in Winter’s Bone. By contrast, First Class finds her playing someone trying to find herself not easy when you’re a mutant shapeshifter.

“The Mystique we know from the original X-Men is a confident, strong, powerful woman,” says Lawrence. “But in this film she’s a kind of insecure girl, who’s discovering herself, her sexuality and her opinion of things.” We’ll see how Mystique morphs from friend of Charles Xavier to Magneto’s right-hand woman. “It starts as a little crush on Magneto but then I start to like his view of the world.”

Her research for the role included ploughing through a vast backstory binder (“I’m still reading it…”) and studying original Mystique Rebecca Romijn’s super-villain slink (“She has a very specific walk!”). She also trained hard two hours a day for five months, only to discover that her stunt double would be taking care of most of the rough stuff. “I was like, ‘Grrr!’ But I guess it meant less time wearing the make-up, so I wasn’t too disappointed.”

She’s guaranteed a bigger slice of the action as the lead in Gary Ross’ upcoming The Hunger Games, adapted from Suzanne Collins’ dystopian bestseller about televised teenage death battles. Before that, you can catch her in Jodie Foster’s The Beaver, playing girlfriend to the son of Mel Gibson’s troubled handpuppet fancier (“It’s about how life can be so dark and messed up that it’s funny”). Not bad going for someone who simply upped sticks to New York at age 14 in search of a talent agent.

Bitten by the acting bug the first time she read a script (“I just loved it”), she graduated from school two years early to get her career going. “All these things started happening,” she recalls. “I started thinking, oh my God, I could do this…”

If there’s a secret to her meteoric rise, it’s self belief. “So many of the decisions I make are based on my guts,” she says. And though she claims that Gena Rowlands’ raw tour-de-force in A Woman Under The Influence (1974) “changed my life”, she’s not out to copy anyone. “I have actors I admire,” she says, “but I’ve never looked at someone and thought ‘I want to be that’ or ‘I want to make that’, because they’ve already done it!” When she’s not working, Lawrence likes to tread a different kind of board. “I really enjoy surfing,” she says. “Although I’m really bad at it!” Guess she’ll have to settle for making waves instead of catching them…

X-Men: First Class features Kevin Bacon as Sebastian Shaw, January Jones as Emma Frost, James McAvoy as Charles Xavier, Michael Fassbender as Magneto, and Nicholas Hoult as Beast. It opens on 29 May 2011 in UK cinemas and 3 June 2011 in the US.