Celebrity Parents Nick and Vanessa Lachey Open Up About Adjusting Their Milestone Expectations for Son Phoenix Of son Phoenix, Vanessa Lachey tells PEOPLE, "We're just living and relishing in what he is doing" By Caroline Redmond Published on January 23, 2018 01:35 PM Share Tweet Pin Email Nick and Vanessa Lachey are getting real about parenting. The couple recently celebrated the 1st birthday of their son Phoenix Robert, who was born 10 weeks prematurely in December 2016, and opened up to PEOPLE about adjusting their expectations when it comes to the youngest member of their family. "What I've had to do for myself now as a mom of a preemie is to not count the milestones," Vanessa told PEOPLE at the Pampers' #SleptLikeThis event in New York. "I mean that loosely and with love — to not compare him because every kid is going to be different, especially a preemie," she adds. Want all the latest pregnancy and birth announcements, plus celebrity mom blogs? Click here to get those and more in the PEOPLE Babies newsletter. Nick Lachey/Instagram RELATED VIDEO: Vanessa Lachey Breaks Down as She Reveals She Underwent an Emergency Surgery During Premature Birth of Son Phoenix For more coverage, follow our babies magazine on Flipboard. The pair — also parents to Brooklyn Elisabeth, 3, and Camden John, 5 — are careful to not compare what their two older kids were doing at 1 year old to what Phoenix is able to do now. "He's smaller, but he's healthy. He's so happy," Vanessa says. "Brooklyn and Camden were standing and walking a little bit at this point and he's not even near that." "And I'm okay with that because every kid has their own time and their own moment," she explains, "and instead of us dwelling on what he's not doing, we're just living and relishing in what he is doing." Nick and Vanessa Lachey Open Up About Premature Birth of Son Phoenix: "We Leaned on Each Other" Phoenix is now a happy and healthy 1-year-old whom Vanessa says is starting to speak a few words and waves just like his dad. Vanessa Lachey/Instagram "He's the happiest, most joyful kid ever," adds Nick, 44. "He's crawling everywhere, he's so curious and into everything now." The adorable family of five recently rang in the New Year on a family vacation in Cabo San Lucas where they celebrated daughter Brooklyn's 3rd birthday with horseback riding and a special dinner.