Keira Knightley was only born because her mother won a bet. "The Duchess" actress - who is dating her "Pride and Prejudice" co-star Rupert Friend - has revealed her playwright mom Sharman Macdonald only fell pregnant after she triumphed in a wager with her husband, actor Will Knightley.

Keira is quoted as saying: "The reason I was born was because they had one child but my mum wanted another baby and they did not have very much money."

Keira Knightley "enjoys" swearing. The 23-year-old star - who claims she doesn't drink, take drugs or smoke - revealed she picked up her only bad habit from her mother, playwright Sharman McDonald.

Keira, who has appeared in period dramas including "The Duchess" and "Pride and Prejudice," told Britain's Daily Mirror newspaper: "That is my vice, swearing, and I really enjoy it. And you know what, my mum swears quite a lot, while my dad does not swear."

Keira Knightley wants to get pregnant so people won't think she is anorexic. "The Duchess" actress - who is often criticized for her slim figure - believes she would get a break from her detractors if she had a baby.

She said: "That's a good reason to have a kid. They won't say I'm anorexic any more. S**t, I've got to have a child."

Keira Knightley has hired a bodyguard after being verbally abused on the street. The actress has been left shaken after a passer-by jumped out at her and screamed obscenities as she walked alone near her home in Richmond, London.

The 23-year-old star spent much of her time in a private room at the after-party following the premiere of the "The Duchess" on Wednesday, as she feared for her safety.

The 23-year-old actress - who plays Georgiana, the Duchess of Devonshire, in period drama "The Duchess" - is "proud" of her modest assets and didn't want them changed in any publicity shots.

A source said: "She has insisted that her figure stay in its natural state. She is proud of her body and doesn't want it altered. But she looks flat-chested throughout the whole movie."

Keira Knightley says she never gets asked out on a date.

The 23-year-old actress - who is dating her 'Pride and Prejudice' co-star Rupert Friend - insists she is never approached by prospective lovers, and wouldn't even notice if she was.