There’s nothing unusual about a celebrity looking gorgeous on the red carpet.

But when Sandra Bullock made the rounds in late October to promote her latest movie, Our Brand Is Crisis, there was definitely something out of the ordinary going on — the 51-year-old stunner seemed to be positively radiating happiness.

And with good reason. Unbeknownst to everyone, she was keeping a joyful secret: Her recent adoption of a little three-year-old girl she named Laila.

sandra bullock and louis

Sandra with her son, Louis, in August 2013.

Now, Sandra is opening up to the world about how she’s spent the past three years navigating the foster system in order to find the perfect addition to her family, which includes son Louis, 5. (Like Laila, he was born in Louisiana.)

RELATED: Sandra Bullock’s Boyfriend Bryan Randall is “So Happy” She Adopted Another Child

“The house is much louder than before, and it never sounded so good,” says the LA-based actress. Indeed, an insider tells Closer that since bringing Laila in the fold, “Sandra really believes her life is complete.”

To read the full story on Sandra, pick up the new issue of Closer Weekly, on newsstands now!