Natasha Gregson Wagner describes it as "the first posed family photo we have taken in a couple of decades"

Natalie Wood’s daughter Natasha Gregson Wagner, marked the 90th birthday of her stepfather, Robert Wagner, by posting a rare family photo on Instagram on Monday. She describes it as “the first posed family photo we have taken in a couple of decades.”

Gregson Wagner, 49, is the daughter of Natalie Wood and her second husband, Richard Gregson. (She refers to Gregson and Wagner as her two dads and calls the latter “Daddy Wagner.”)

To mark Wagner’s 90th birthday on February 10, Natasha writes, “My sisters and I did not know what to give my Dad for his 90th birthday. What in the world do you give a 90 year old? Katie (Wagner’s daughter with second wife Marion Marshall) had the great idea of having her dear friend and pretty rad photographer Greg Gorman take a picture of us.”

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“Then we figured why not have Dad and Jill in the photo too,” she adds, referring to Wagner and wife, Jill St. John, whom he married in 1990.

Natalie Wood with Robert Wagner and Natasha
| Credit: Globe Photos/Shutterstock

In the photo, Natasha poses with her daughter, Clover, Jill St. John, Wagner, Katie Wagner, her son, Riley, and her sister Courtney Wagner.

As she writes, “Hope we all get to age as gracefully and joyfully as our dad.”

Natalie Wood
Natalie Wood
| Credit: Silver Screen Collection/Getty

After her mother’s death in 1981 at age 43, Natasha was raised by Wagner, along with her younger sister, Courtney, the daughter of Wagner and Wood. This was done so that the two girls, along with Katie, could remain close after the devastating loss of their mom.

Wood’s death by drowning off of Catalina Island shattered Natasha, then eleven years old, and her family.

As she told PEOPLE in 2016, “I grew up always thinking I had two dads. I’m certain because my mom died, my relationship with my stepdad is way deeper than it would have been had she lived, because he had to be my mom and dad.”

Natasha is currently working on two projects that honor their mother, the legendary movie star known for her roles in West Side Story, Splendor in the Grass and Rebel Without a Cause, among others.

She’s written an upcoming book, More Than Love, to be published this May, in which she tells her story and her mother’s story — in depth for the first time. In conjunction, she’s collaborated on an HBO documentary What Remains Behind.

It’s all part of her journey to reclaim her mother’s story, one that was often told by others, following her death; she also launched a line of fragrances called Natalie, in her mother’s memory, a new take on her mother’s signature gardenia scent.