Sienna Miller - Birth Of Sienna Miller's First Child Shrouded In Mystery

The pair have been dating for over a year, with Miller debuting her dazzling engagement ring in mid-February. A source confirmed to US weekly magazine that the actress had become a mother for the first time, though could offer nothing more concrete in terms of details. Sienna, 30, opened up to British Vogue in April about the pregnancy, saying, "Even though I'm under strict instructions not to say anything as it would completely defeat the point of everything I've tried to achieve in the last eight years.I'm feeling fine...It's all progressing nicely and it's very exciting". Despite the couple's silence about their new addition, Miller and Sturridge have not hesitated to step out in public in recent months. Most recently, the couple jetted off to Portofino, Italy, while a week later, they celebrated Robert Pattinson's 26th birthday at Gordon Ramsay's restaurant in London.

Miller's reluctance to provide details of her personal life may be linked to her previous relationship with Jude Law, which was intensely scrutinized by the tabloid press. The eventual breakdown of their romance was also played out on the front pages. Despite her pregnancy, Miller has no less than six projects in the works, including British-set comedy drama 'Hippie Hippie Shake'.