“I think in our business, it’s always a little bit tricky to navigate things because it’s not like a normal job where you know where you’re going to be the next year, let alone the next day. You just don’t,” the actress, 34, tells PEOPLE.
Mara and Bell have been dating since fall 2015, and PEOPLE confirmed their engagement in January. The two previously costarred in 2015’s Fantastic Four, and were spotted out together multiple times after the film’s release.
In her latest film, Megan Leavey, Mara stars as a real-life Marine corporal who develops a deep bond with her military combat dog while deployed in Iraq.
She’s also starring as the late Mary Jo Kopechne in Chappaquiddick, a film about Ted Kennedy and the young woman who died in a 1969 car accident involving the senator. Other upcoming films starring the actress include Mercy, opposite Ellen Page, and The Heyday of the Insensitive Bastards, based on the novel by Robert Boswell.
With all of those projects in the works, Mara says the secret to making a relationship work is flexibility. “You constantly have to shift things, and communicate,” she says. “Like asking, ‘What’s your deal with that show or with this movie,’ to make sure that you actually can see each other.”
Mara makes time for her relationship the same way she’s made time for her family in the past. “You have to find ways of sacrificing work so that you can be with your family,” she explains. But dating a fellow actor, and having another actor in the family (her sister is actress Rooney Mara) helps everyone adjust expectations.
“I think that’s the most important thing, especially when you’re in a relationship with another actor, because it’s tricky,” she says. “We’re on the same page though, so that helps.”