The amicable exes, who split in 2007, share two children together -- Deacon and 18-year-old Ava, who also posted a moving birthday message to her brother on Instagram.
"#14 years ago today!! Happy birthday, @deaconphillippe! Congrats on being way cooler at 14 than I am at 18," Deacon's big sister wrote. "I’m so lucky to have you around. Love you so much, and I hope you have an awesome day! ❤️??."