Emily Blunt is such a timeless beauty.

It’s hard to believe that in the 10 years since we first met her in The Devil Wears Prada, for which she won the Golden Globe, she’s made – believe it or not – 25 films, most of them forgettable. But four stand out: Young Victoria, Edge of Tomorrow, Sicario and Into the Woods.

Now, she’s playing the complex Rachel in The Girl On The Train, based on the novel which has sold 15 million copies worldwide, and after that she’ll be devoting eight months to a remake of Mary Poppins.

Her personal life has been equally productive.

Married to actor John Krasinski, they have two beautiful daughters, the youngest is two months old.

In New York for the film’s junket, the 33-year-old English actress is as relaxed as ever – the epitome of unaffected professionalism.

Not only is she married to an actor, her brother is an actor, and her sister is married to her The Devil Wears Prada co-star Stanley Tucci (she introduced them).

Knowing that her father is a practising barrister, I wondered how he’s adjusted to his newly acquired theatrical clan.

Getting my drift she smiles broadly.

“My father defends criminals for a living, so I am sure he feels that he is the biggest actor in the family. He literally lives a lie every day, and most of the people he defends are usually guilty. So, I don’t know. I think it makes him laugh. We are very good at charades. It’s loud and boisterous. Although I am sure he would prefer not to be known as Emily Blunt’s father, and he would like to be known as Oliver Blunt in his own right,” she replies.

After accepting the role in The Girl On The Train, you found out you were pregnant, why did you choose to hide it?

It was a week before we started shooting. So I was like, this will be interesting. You can hide it for a great deal of time, but I think the first 12 weeks – as every mother knows – is frightening and you hope everything is going to be OK.

It was only when (co-star) Justin Theroux, who is my dear friend, took me aside because I was being a bit wussy about some of the stunts, and remarked, “You did Edge Of Tomorrow, what is wrong with you? Are you pregnant?”

I was like, “Yes! Don’t tell anybody!”

So, he guessed and because we had quite a few tussles in the film, he had to be careful about what he couldn’t do in those scenes.

And even the director wasn’t told?

We started shooting in October and I didn’t tell him until January, and then only because I was really showing by then. We were doing a scene in the bathtub, and I was like, you are going to have to shoot this from behind, and this is why.

Working with a director who has a special rapport with women – Tate Taylor had guided three actresses to Oscar nominations for The Help – was that a plus?

Yeah. I think I have been lucky. I have worked with quite a few directors who have a profound understanding of women and are interested with what you can bring to the table.

Tate is a collaborator. On the set it was always the best idea would win, no matter who it came from. And so between him and the cinematographer, the three of us would very often just come in and hash it out.

And everyone had a very spirited opinion. Tate is unaffected by that. He doesn’t have that ego of wanting it to be his way.

Emily Blunt is the girl on the train ... to London, not Busan. Photo: UIP

Emily Blunt is the girl on the train … to London, not Busan. Photo: UIP

Is there anything you’ve leaned from making this movie?

Yes, that women are quite often a bit judgmental of each other. It’s a social currency to talk about each other, the ins and outs of someone’s marriage or the demise of their marriage, or the fact that they can’t have children. It’s sort of a tantalising subject.

And I think because it’s so personal to us, it’s something that we all want to know about each other. But I think it can make women defensive of their choices. I think we can be a little hard on each other when it comes to the domestic environment.

You’ve been working almost non-stop for the past few years. Will you continue to do so with a growing family to look after?

I am now very much aware and conscious about what I want to put out there and when I want to work. It has to be very emotionally worth it and I have to love it, because as you say I have children at very tender ages and there’s that juggle to contend with.

Will you be trying for a boy now?

I am thrilled with my girls, thrilled.

And John?

He is from a family of all boys. He is thrilled with all girls.

So what are you learning from your kids?

I think you rediscover life through their eyes. You will never laugh as much until you have a kid and you rediscover a bit of wonderment about the world and everything about it, from a skyscraper to how blue the sky is. It’s a voyage of discovery, isn’t it?

It’s like your heart walks around outside of you, So yeah, I am rediscovering more of life through their eyes.

How excited are you about playing Mary Poppins?

I have a Mary Poppins right now helping me with my own children, We call Tina our Irish Mary Poppins.

So when (director) Rob Marshall called me, he left a sort of a cryptic message. So, I called him back, and as soon as he uttered the name Mary Poppins – it’s such a sensory name that conjures up so many nostalgic memories for people – I was filled with a mix of fear and excitement. Because she is so iconic and emblematic for so many people, I just have to try to do my own version of her. We rehearse for two months, and then we pre-­record, and then we shoot for four or five months. It will be like an eight-month process.

Did you ever meet Julie Andrews (who played the the character in the 1964 film)?

I met her years ago and she was really lovely to me. But, actually, I have a story I’ve never told anyone before, which is about four years ago, John and I were in Ojai, and we went to this little farmer’s market and there was a woman who had made beautiful little art pieces out of flowers and seeds and leaves – it was the most incredible, intricate, beautiful images in these little art pieces.

And we bought one of Mary Poppins. And this was way before I had children or any idea this would happen. And it’s sitting at the top of our stairs now.

Do you feel pressure to look a certain way, which is problem for so many women. And could eventually impact your daughters?

It definitely worries me, and that was a big part of us deciding to move to New York.

The biggest star in New York is New York itself. It’s a city that is not bogged down in a look or being too superficial or looking too perfect. It feels more grounded here for two girls.

What do you miss most about London?

There’s an attitude in English people I miss, a sort of irreverence and shoulder shrugging attitude that I miss when I am in America.

And I miss the pubs and the really soggy chips from a fish and chips shop. Of course I have Marmite everywhere in my house. I am still trying to persuade John that it’s a good thing, but he is like, “It’s yeast!”