'Your life is chaos and you're exhausted': Sienna Miller looks sensational in plunging black dress in Vogue magazine... as she reveals the downsides to motherhood

She doesn't often open up about her personal life.

But Sienna Miller has revealed her true feelings about being a working mother alongside a stunning photo shoot in the new issue of VOGUE magazine.

The 33-year-old British actress oozed old-school Hollywood glamour - and a touch of sex appeal - in buckets as she posed in a beautiful editorial shot inside the October issue of the fashion tome.

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Gorgeous: Sienna Miller looks sensational as she appears in the October issue of VOGUE magazine, wowing in a low-cut black dress with an old-school Hollywood vibe as she discusses motherhood

Gorgeous: Sienna Miller looks sensational as she appears in the October issue of VOGUE magazine, wowing in a low-cut black dress with an old-school Hollywood vibe as she discusses motherhood

Wearing a plunging black dress that showed off her pert chest, she looked immaculate as she posed nonchalantly on a cream sofa.

The formal gown was a perfect fit for her slender figure, the skirt mid-length and including a stylish large peplum detail that was almost obscured thanks to her seated poise.

Extra retro elegance was added with cream gloves up to her elbows, and gorgeous cream ankle strap heels. 

The blonde beauty's bob haircut was coiffed into almost wet-look curls, which worked perfectly against her vibrant scarlet lip colour.

'We just run ourselves ragged': Sienna - a doting mother to her three-year-old daughter Marlowe - loves being a parent, but confessed the challenges that she faces 

'We just run ourselves ragged': Sienna - a doting mother to her three-year-old daughter Marlowe - loves being a parent, but confessed the challenges that she faces 

It was certainly a more sultry look than the one she rocked on the cover, the actress looking the perfect combination of adorable and drop-dead gorgeous in red, beaming widely.

Emblazoned across the long-running fashion magazine's front cover, Sienna is called 'A girl of our times'. 

Along with the glossy editorial, Sienna opened up about motherhood - she is the proud mum to her three-year-old daughter Marlow with ex-fiance Tom Sturridge, from whom she split earlier this summer.

However, jugging being a mother and having a career as an actress isn't something that comes easily to her. 

Love split: The 33-year-old actress shares her daughter with her ex-fiance Tom Sturridge, who she reportedly split from earlier this summer

Love split: The 33-year-old actress shares her daughter with her ex-fiance Tom Sturridge, who she reportedly split from earlier this summer

'Obviously when you have a baby it's the most incredible experience but your life is also catapulted into this chaos and you are exhausted,' she said. 

'I could literally get on this table and fall asleep. I'd like to be better at managing things; I'd like to be more super - although we're never going to feel it, even if we are. 

'That's the curse of motherhood – we just run ourselves ragged. I'm just trying to get a sense of what that guilt is. I sometimes feel like it's a totally invented emotion. It's strange to be punishing ourselves this way. It's not healthy.' 

But, although she admits she feels exhausted much of the time and that she 'runs herself ragged', Sienna certainly looked impeccable in the accompanying shoot.

Fashion star: In the VOGUE interview, Sienna also claimed she 'wears jeans and trainers and a t-shirt most days'... but always looks amazing when she steps out on the red carpet

Fashion star: In the VOGUE interview, Sienna also claimed she 'wears jeans and trainers and a t-shirt most days'... but always looks amazing when she steps out on the red carpet

In the open and honest discussion and rare personal insight into her life, the American Sniper actress also touched on her relationship with her mother and sister Savannah. 

'I'm really close to them, they are hugely important and influential women in my life, but of course we drive each other nuts as well!' she confessed.

As well as being a big-name silver screen star, Sienna is also known for being one of the best dressed people in showbiz, although she claims she isn't the most active shopper. 

She added: 'I don't remember the last time I went shopping. I swear to God, I wear jeans and trainers and a T-shirt most days.' 

See the full shoot in the October issue of VOGUE, on sale Thursday.

Read all about it: Sienna covers the new issue of VOGUE magazine, on sale on Thursday

Read all about it: Sienna covers the new issue of VOGUE magazine, on sale on Thursday

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