Sandra Bullock

The 49-year-old star has reportedly begun filing paperwork to adopt another child to give her three-year-old son Louis - whom she adopted in 2010 as a newborn - a sibling to grow up with.

A source told National Enquirer magazine: "Being a mum means more to her than anything - her Oscar, her career, her fame, her fortune. She was born to be a mom. She has a son and soon she may have a daughter."

The 'Gravity' actress' first adoption took four years to complete and much like that experience, pals close to Sandra insist she isn't looking for special treatment despite her worldwide fame.

The insider told National Enquirer magazine: "Just because she's rich and famous doesn't mean that Sandra expected, wanted or got any preferential treatment. That is not her style."

Perhaps a sign the Oscar-winning star may be adding to her brood, pals claim she has cleared her schedule for the next year - except for a voice role in new animated comedy 'Minions'.

The source added: "Other than that, she just has a tiny handful of projects that haven't even made it to the script stage yet. Her schedule is wide open."