Sandra Bullock Opens Up About Her Family: It's 'Not How Most People Thought It Would Look'

Sandra Bullock is counting her blessings for the way her family has come to fruition.

The actress — whose new film Bird Box is in theaters now — opens up to PEOPLE alongside costar Sarah Paulson for this week’s issue, explaining how her life has become even more enriched since welcoming daughter Laila, 6½, and son Louis, 8½.

“We’re very lucky that we get to live in this moment in time where we get to choose what our family looks like, and I got to do that in real life,” says Bullock, 54.

“You imagine so many things for yourself, but when it appears it’s better than anything you could ever imagine. And in [Bird Box], it is about family in a sense, in that ‘sight’ has us choosing things based on a preconceived notion of what that image must be like, when in fact it’s the exact opposite.”

“And here are these people who have that taken away, and you are actually given the family that is going to take the best care of you, that wants to take care of you, that wants to be there for you, and how that that looks is very different from what most people expect,” she adds. “But I think what I loved about this is that it sort of mirrored what I feel about real life, in that my family is not how most people thought it would look, but it’s better.”

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Bullock — who severely dislikes being scared to the point where she jokes Ellen DeGeneres is “a horrible human being” for scaring people on her show — says her own biggest fear is “being away from my children.”

“It was a lot of hard, sad days [on set],” she recalls. “There was a day that I had to do this speech about [Sarah] and we were in the house, and you just have to get to the place of, ‘I’m going to have to start thinking about things that no one wants to think about.’ “

“But that’s what the movie’s about — what is my greatest fear?” Bullock adds of the apocalyptic thriller, where she and Paulson, 44, play sisters. “I had to think about it all the time.”

Paulson has the highest praises to sing about her costar, calling Bullock “an incredible mother” and “an incredible girlfriend” who “takes care of every single actor on the set,” “knows every member of the crew” and is “genuinely interested” in everything and everyone around her.

“It was an incredible thing to see someone who is at the top of their game who has been at the top of their game for a long time, and who is always meeting with a kindness and awareness of other people,” she added.

For more from Sandra Bullock and Sarah Paulson, pick up the latest issue of PEOPLE, on newsstands Friday.