Both stars took to their personal Instagram accounts on Monday, May 10 to announce the birth of daughter Rio by sharing the same precious photo of the couple holding the newborn's hand. In their message, the Hawaii-based pair, who also share sons Ocean, 4, and Kingston, 22 months, explained that their baby girl arrived sooner than expected and is currently resting in the Neonatal Intensive Care Unit (NICU).
"SO.. we've been MIA these last few days," the 32-year-old Sleepover actress captioned her post. "Let's just say we learned once again that God is always in control. You may have a PLAN for your life, but all that really matters is HIS plan. Little Rio could not wait to come out and play with her brothers! Momma is feeling good and baby girl is kicking some serious booty in the NICU."
Alexa, known for her starring role in the Spy Kids franchise, continued, "Praying we can all be home together very soon! What a wave of emotions. Much love and thanks to all the Nurses, Doctors from Maui to Oahu - who brought little Rio safely into this world."
For his part, Carlos, who wed Alexa in 2014, shared the same message but also added a few lines of praise for his wife.
"Can't wait to share the story with you all!" the 31-year-old Big Time Rush star wrote. "I lift up my wifey @vegaalexa on this Mother's Day. YOU ARE A CHAMP! I could never do what you do. The best momma to our 2 boys and now little girl. Thank you for being a solid rock for this family."
Among the celebs sending support in the comments was Alexa's bestie Nikki Reed, who posted, "I love you Mama! All my strength and love to you, Los and all THREE babies!" Appropriately, Nikki also included three red-heart emojis.
Robbie Amell, who co-starred with Alexa in the 2013 Hallmark Channel film The Hunters, wrote, "I hope everyone is safe and healthy [string of heart emojis]."