Emily Blunt on Her New Role, New Baby and Husband John Krasinski

— -- There’s already Oscar buzz around Emily Blunt’s performance in “The Girl on the Train,” a new film that is an adaptation from the bestselling book.

But Blunt had mixed feelings about being chosen for the lead role in the film.

“I read it and I was at the same time thrilled by the challenge of the character but also slightly concerned that they’d just think immediately of me for somebody who is described as sort of a puffy-face, aggressive, obsessive alcoholic,” Blunt joked in an appearance on ABC News' “Popcorn with Peter Travers.”

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Fans of the book will note that the story's setting was changed from London to New York for the film. Blunt, who is British, told Travers she was open to switching to an American accent for the role.

“I did offer to do an American accent, which I have done for a couple of films before,” Blunt said. “Tate Taylor, the director, quite liked [her British accent]. And he said, ‘Well, I think this character’s really isolated. So why don’t you just keep it and keep her as isolated as possible.”

Blunt plays the role of Rachel Watson whose character witnesses a murder. But because she’s an unhinged alcoholic, she makes less than a perfect witness.

“It’s less a thriller about Rachel being a terrible, drunk, Nancy Drew character trying to figure out who done it,” Blunt, 33, told Travers. “It’s more about her trying to make sure she didn’t do it. And I think that was so appealing and unsettling and weird to me. And that’s what I really liked about the character.”

Be sure to watch the full video above to see Blunt talk more about her role in the film, how she first met husband John Krasinski and about being a new mom. “The Girl on the Train” is in theaters everywhere today.