She is the quintessential English rose who is renowned for scene-stealing roles in such movies as The Devil Wears Prada.
But actress Emily Blunt, 33, has faced criticism from book fans, who have slammed her casting as Rachel Watson in the screen adaptation of Girl On The Train, according to the Daily Mail.
And now the bestselling novel's author, Paula Hawkins, has revealed that the "too beautiful" actress was made to "look a bit s**t" for her role in the gritty drama.
The 44-year-old recently told an audience at the Chiswick Book Festival that she had already seen a cut of the film, which opens worldwide next month, and praised Emily's "extraordinary" performance.
Admitting she was a fan of the actress, Paula said: "I love Emily Blunt. Mostly, I thought of her as like a comedy actress.
"I remember her sort of scene-stealing role in The Devil Wears Prada, but she does the most extraordinary job in this. She really does.
"Everybody moans about, 'Oh, she's too beautiful to play Rachel' and she is [too beautiful]. But the thing about Rachel, you know the key part of her is her self-loathing and how bad she feels about herself."
The writer went on to say that the way the actress "carries herself" managed to capture the way her character feels "horrible" about herself "amazingly" well.
Referring to the film crew, she added: "They've done their best, I mean to sort of make her look a bit s**t, but you know..."
Paula also revealed that she's been axed from her own movie - having visited the New York City set and appearing as an extra during a scene at Grand Central station, which Emily's character commutes into.
"I was actually in a shot there, although apparently it's been cut," she said.
The movie, which will enjoy its premiere in London's Leicester Square, features Emily playing a frumpy, overweight alcoholic divorcee who obsesses about a couple she sees every day from the train window on her morning commute.
After the wife disappears, Emily's character inveigles her way into the police investigation and attempts to recall what has really happened while in an alcoholic haze.
In the movie trailer, Emily is seen looking worlds away from her glamorous self, with her hair left mussed and her skin blotchy and reddened by her character's alcohol abuse.
With tears streaming down her face and a quivering voice she says: "I used to watch this perfect couple. They were the embodiment of true love."
In an interview with the Daily Mail in 2013, she described how she plays the Hollywood game, but it has its downsides.
She said: "It's not celebrity per se. But the fact is that as an actress you're always expected to look perfect, wear the latest design and look your best.
"Sometimes you want to wear a T-shirt and jeans when you go to the grocery store or to a cafe and read a book or magazine.
I also feel bad for women in their late 30s or 40s because there's so much pressure in this business to look young that women are not supposed to age.
"It's terrifying to think that when I'm 40, a lot of roles will be closed to me because of that kind of age bias.
"I don't want to think that I have to maintain eternal youth."
In an interview last week, she described to The Sun how it was "liberating" to play such a complex character who's life's falling apart in The Girl on the Train.
She said: "I haven't played a woman like Rachel before. Alcoholism is a brutal disease and it exacts a terrible cost on the people who suffer from this addiction and the people around them. It was a great challenge to play a very messy, broken character."
The Girl on the Train also stars Justin Theroux, Luke Evans and Rebecca Ferguson.
London native Emily married American actor John Krasinki in 2010 and they have two children: Hazel, two, and Violet, three months.
She discovered she was pregnant with Violet while filming The Girl on the Train.
Emily gained BAFTA and Golden Globe nominations for Best Supporting Actress for her portrayal of the ambitious assistant to Meryl Streep's nightmare magazine editor in The Devil Wears Prada.
In May, Walt Disney Studios confirmed the mother-of-two will star in Mary Poppins Returns.
More than 4.5million copies of The Girl on the Train have been sold in the US alone.
It has been compared to another smash hit, Gone Girl, by Gillian Flynn, which was also made into a movie in 2014 - grossing more than £129million (NZ$230million).
Girl On The Train opens in New Zealand October 6.