Daniela Ruah and her fiancé David Olsen got a belated Christmas present on Monday, December 30. Five days after the couple celebrated the holidays, they welcomed their first child, a son named River Isaac Ruah Olsen.

“He’s healthy and strong, which is all we could ask for,” the NCIS: Los Angeles star, 30, tells PEOPLE. “We are so happy, so thankful and feel so blessed to have brought him into the world.”

Daniela and David announced that they were expecting back in September. “I’m so thrilled about this new chapter as a parent with David,” she said at the time. “It’s amazing how in love I am with this little person I’ve only seen on a black and white screen. I’m starting my own family and there is no other feeling like it.”

Daniela posted a photo of River and David’s hands, on Instagram, with a caption that read: “Heaven, I’m in heaven… And my heart beats so that I can hardly speak #mytwoloves.”

Congratulations to the happy couple!

Image via Twitter