Samaire Armstrong attends 'The Mentalist' 100th episode celebration on October 13, 2012 in Los Angeles, California. Credit: Paul Archuleta/FilmMagic

Samaire Armstrong is a mommy!

The Mentalist actress, 32, gave birth to her first child, son Calin, a source confirms to Us Weekly.

The new mom shared the exciting news on Facebook Sunday, Dec. 16, writing, "Thank you so much for all the love! Will post pictures after a little rest. We're all doing wonderfully. It was an amazing experience and we couldn't be more thrilled with our new arrival. xoxo!"

Armstrong, who confirmed her pregnancy on Twitter in October, had been counting down the days until her baby boy arrived on Facebook.

"Ok baby. We're ready when you are," she wrote Friday. "Eight day count down . . . 8 days?!"

She shared a photo of her bare baby bump on Twitter in November with headphones around her belly. She captioned the shot, "Maybe he'll be a lawyer."