The actress, 44, has just been cast in her most rewarding role yet: Mom. She's adopted a 9-month-old baby boy from Ethopia, Britton tells PEOPLE exclusively.
After a three-year-long adoption process, the actress's dream of motherhood came true about a week ago, after she returned from the African country with her son Yoby – a nickname for Eyob, his given name.
"I am thanking my lucky stars every day," Britton, 44, tells PEOPLE.
The day she first held her son in her arms was something the new mom will never forget.
"It was such a wonderful moment of completion," she says. "I thought I was going to collapse into a puddle of tears. I was just grinning from ear to ear."
Aw, congratulations to her!