If acting didn’t pan out, Taissa Farmiga might have been an accountant. It all started when her famous sister Vera (Oscar nominated for 2009’s Up in the Air) pulled Taissa, reluctantly, onto a film set. “I was thrown into this world,” Taissa told Yahoo Movies with a laugh during a recent phone call, recalling her first film role in the 2011 drama Higher Ground, where she played the teenage version of Vera’s character. (It was also Vera’s directorial debut.)

Known for her run on FX’s American Horror Story, the younger Farmiga appears in an exclusive trailer (above) for the Duplass brothers-produced film 6 Years, directed by relative newcomer Hannah Fidell and also starring Ben Rosenfield (Woody Allen’s Irrational Man). In it Farmiga and Rosenfield play the young couple Mel and Dan, who have stuck together through high school into their early 20s.

“She’s growing up and trying to figure out how to handle her emotions,” says Farmiga. Twenty years old herself, she relates to her character. “It’s her first serious relationship and I was going through similar things at the time. Learning how to communicate is a big thing I got to discover… I like to play new people because it helps me figure out how to be them and [in turn] it helps me figure out who I am.”

Fidell, Rosenfield, and Farmiga first needed to cultivate a bond off-screen. The trio went away to the Berkshires in western Massachusetts before production started to study the script outline and decipher their character backstories. “We could draw on past experiences that weren’t really there.” One of them was that Mel and Dan’s first concert together was Wilco. It’s a small detail, which informed Farmiga and Rosenfield’s performance, that doesn’t actually show up in the film.

The prep work was essential as the film is largely improvised. “We had the structure of what we needed to get across but how we said it was usually up to me and Ben,” says Farmiga. “We had to draw from our personal experiences.”

But depicting such an intimate partnership can get tricky — especially for young performers. “It’s always a little awkward on your first day on set when you have a making-out scene,” says Farmiga, acknowledging it gets especially weird when she’s in an off-screen relationship with someone else. “You just have to let yourself go.”

A quick look at her IMDb page might indicate Taissa Farmiga has been working steadily ever since Vera got her into the business. But there was an initial lull. “After Higher Ground about six months went by and I went back to my normal life and, honestly, I was looking at community college classes for accounting. I wasn’t jumping right into it, thinking, ‘I have to be an actress,’” Taissa recalls. Now, she has fully embraced it — almost 100 percent. “About 5 percent, there’s that accountant inside of me pumping out numbers… but I kind of have my own college experience now.”

6 Years is on iTunes and VOD Aug. 18.