Shailene Woodley is in ascent

You always remember your first time. Even at the movies.

Firmly planted in that unforgettable category is Shailene Woodley’s big-screen debut in The Descendants, a glowingly reviewed comedy-drama serving up dysfunctional family life Hawaiian-style.

Woodley, 20, best known as a high schooler coping with single motherhood on the ABC Family series The Secret Life of the American Teenager, already boasts a rather exclusive fan club for her film work: her co-star, her director and the author who wrote the novel upon which the script is based.

“She’s a 50-year-old scientist in a 20-year-old body,” raves George Clooney, her movie father. “She’s not intimidated by anyone.”

“She’s the cat’s pajamas,” extols Alexander Payne, the Sideways filmmaker who was seeking a young Debra Winger type (“vulnerable and fiery”) when he hired Woodley. “She is going places.”

“I felt like I got the opportunity to hang out with a future star,” exclaims writer Kaui Hart Hemmings, who is seen as Clooney’s secretary in the movie.

At year’s end, when studios launch their best hopes for Oscar attention, there usually is one or two Cinderellas poised to step into the lead or supporting-actress category.

It might be Woodley’s turn, thanks to her knockout performance as Alex, a recovering addict whose profanity-laced resentment toward her distant dad gradually shifts to respect after her mother falls into a coma.

“She really elevates that role from a stereotype,” Clooney says with paternal pride of his movie daughter, who has been acting on TV since she was 5. “You can write and direct it. But at the end of the day, someone has to play it.” The scene that grabs ’em every time: Alex’s breakdown in a pool after being told tragic news. “She cries underwater,” marvels the actor.

Woodley sounds spellbound by her chance to work with some of the best in the business on her first feature.

Asked about the hubbub surrounding the film festival premiere and party the night before, the Simi Valley, Calif., native, who still lives with her mom, lets out a typical “awesome” before weaving a more metaphorical reply.

“When we were filming, we weren’t making a film. We were making a piece of art,” says Woodley with a honey-on-sandpaper catch in her voice that recalls sassy screwball heroines of yore. “The sound guy was an artist in his department. The craft service guy was an artist. The actors were artists. The transportation guy was an artist. Everyone came together every day to paint a canvas. So last night was a celebration of that canvas.”

She is even more ardent about Clooney. “Every positive thing that has ever been said about George Clooney is true,” she assures, “and every negative that has been said about him is a lie. Literally. This man does not have one mean bone in his body. The first thing he ever did with me was to give me a hug and say, ‘Welcome, sweetie.’ ”

But she is most awed by Payne, who had the foresight to bring Woodley and Amara Miller, who plays her headstrong 10-year-old sister, together with Clooney to Hawaii two weeks before shooting began so they would comfortably connect.

“I don’t know if I’ve said this yet,” says Woodley, “but he is one of my top five favorite people. I get teary-eyed thinking about his greatness. He is one of those men who stops and thinks before he speaks.”

She would love to capitalize on her momentum and sign on for more films, but she is committed to her TV show — which is about to enter its fourth season — for another two years.

“Whatever happens, happens,” Woodley says with a smile. “I’m in no hurry. I am very grateful for every day.”