Carys Zeta Douglas celebrated a big milestone birthday this April 20 as she turned 18. Her parents ushered in the festivities with posts to their social media, each celebrating the life and love they've gotten to share with their daughter thus far. Carys is the daughter of Catherine Zeta-Jones and Michael Douglas. She's also the younger sister to brother Dylan Michael, born in 2000. She is half-siblings with Cameron Douglas, whose mother is Diandra Morrell Douglas (n\u00e9e Luker). Michael Douglas wishes Carys the best 18th birthday anyone could hope for View this post on Instagram A post shared by Michael Douglas (@michaelkirkdouglas) On April 20, Michael Douglas took to Instagram offering Carys a heartfelt message for her milestone 18th birthday. "Honey this is your Dad, wishing you the best 18th birthday any young lady could possibly have," he wrote. View this post on Instagram A post shared by CZD (@carys.douglas) RELATED: Catherine Zeta-Jones Shares Rare Candid Picture Of Children Dylan And Carys After well wishes, accompanied by a picture of father and daughter together, he went on to share what he loved and loves about her. "You know how much I love you, how proud I am of you, and the joy I have watching you grow into the young lady you are turning out to be! Happy birthday Carys! I love you! Dad." Catherine Zeta-Jones takes a beautiful walk down memory lane View this post on Instagram A post shared by Catherine Zeta-Jones (@catherinezetajones) On the same day, Carys' mother Zeta-Jones shared a tender message honoring the memories they've shared. "Happy 18th Birthday Carys Zeta!" she gushed. "You are everything, and everything is you. Thank you for the joy you bring me. At 5 am this morning, you texted me to thank me, for giving birth to you." View this post on Instagram A post shared by Catherine Zeta-Jones (@catherinezetajones) She then focused on praising the woman she's become, adding, "That\u2019s the kind of woman you are. Kind. Your wisdom out numbers your years. You beauty is deep and your heart is big enough to love and envelop the world, your sense of humor......very important.... is insurmountable. I could go on. Your Japanese needs some work, but that\u2019s doable. I love you angel. Mama." Carys, in turn, offered gratitude in the replies, writing, "I love you my mamma! Thank you for all that you do."