Mark Wahlberg pays tribute to late sister on daughter's 18th birthday: 'Guardian angel'

The birthday of Mark Wahlberg's oldest child is also a bittersweet day for his family.

Wahlberg celebrated his daughter Ella's 18th birthday on Thursday while also marking 18 years since the loss of his sister Debbie, who died at 43 in 2003 on the day Ella was born.

The actor shared a photo on Instagram of him with Ella as a toddler as well as a throwback shot of him with his arms wrapped around Debbie.

"Happy B day my Ella????18 years old ??wow how time flies," So proud of you !! Always A bitter Sweet day . Missing my big sister Debbie??Ella’s Guardian angel????????"

Debbie was one of Wahlberg's eight siblings, while Ella is his oldest of four children with wife Rhea Durham. The couple, who celebrated their 12th wedding anniversary last month, are also parents to Michael, 15, Brendan, 12, and Grace, 11.

Durham also celebrated Ella's milestone birthday on Thursday with a photo of her daughter in a Bart Simpson shirt on Instagram.

"How are you 18!?!?" she wrote. "Happy Birthday my sweet, smart, FUNNY, beautiful, kind & no crap taking girl! Make 18 your best year yet!!???????????♀??????♀?????????????"

Ella also got some birthday wishes in the Instagram comments from actors Jeremy Renner and Mario Lopez as well as a pair of sports luminaries, retired boxer "Irish" Micky Ward, whom Wahlberg played in the 2010 movie "The Fighter," and New York Yankees Hall of Famer Mariano Rivera.

The woman who raised Mark, Debbie and their seven siblings, family matriarch Alma Wahlberg, died at 78 in April. Mark and his brother, "Blue Bloods" actor Donnie Wahlberg, paid tribute to her in May on what would've been her 79th birthday.

"Happy birthday mommy?? " Wahlberg wrote on Instagram.