Mark Wahlberg honored his late sister as he celebrated his daughter's 18th birthday Thursday on social media.

"Happy B day my Ella," Wahlberg captioned two throwback photos. One photo featured the "Joe Bell" actor and his daughter as a baby and the other featured him with his older sister, Debbie.

"wow how time flies. So proud of you !! Always A bitter Sweet day . Missing my big sister Debbie," he added. "Ella’s Guardian angel."

On the day Wahlberg's daughter Ella was born, his sister had a heart attack and died, according to People magazine.

MARK WAHLBERG CELEBRATES 12 YEARS OF MARRIAGE TO RHEA DURHAM

Mark Wahlberg's daughter, Ella, was born on the same day his sister died from a heart attack. The actor honored his late sister in a birthday post for his daughter on social media.

Mark Wahlberg's daughter, Ella, was born on the same day his sister died from a heart attack. The actor honored his late sister in a birthday post for his daughter on social media. (Reuters)

Wahlberg used his experience as a father to help him prepare for his role in "Joe Bell."

CLICK HERE TO SIGN UP FOR THE ENTERTAINMENT NEWSLETTER

The actor portrays the true story of blue-collar dad from Oregon who made it his mission to spread the message of anti-bullying after losing his 15-year-old son, Jadin, to suicide in 2013. It's revealed in the film that Jadin, a sophomore in high school, had been subjected to ruthless mistreatment at school and on social media over his sexuality.

A bereaved Joe Bell would quit his job to launch the foundation, Faces for Change, in his son’s honor and later pressed forward with an idea of walking across the continental United States to campaign against bullying.

CLICK HERE TO GET THE FOX NEWS APP

"Hopefully it would, maybe bring some healing and more importantly, prevent other families from having to go through the same thing," Wahlberg told Fox News.

Fox News' Julius Young contributed to this report.