The actress and her Good Charlotte rocker husband announced they were new parents to daughter Raddix last month, January 2020 in an Instagram post and, taking to the platform again, the 40-year-old guitarist reflected on his new role as a dad.
"My Wife and Daughter fill me up with so much gratitude," Benji wrote on Instagram alongside a drawing of some roses. "Everyday, I feel so lucky."
He added, "Just wanted to say it out loud!!! Much Love & Best Wishes."
The tot, who was born on December 30, 2019, is named Raddix Chloe Wildflower Madden.
"She has instantly captured our hearts and completed our family. While we are overjoyed to share this news," wrote Diaz as she announced the happy news.
She also said the couple has a "strong instinct to protect our little one's privacy," and refused to share any further information or photographs online.
The fiercely private couple wed in 2015. Raddix is the stars' first child.