Sarah Michelle Gellar Shares Why Robin Williams' Death Forced Her to Take a Break from Acting

Sarah Michelle Gellar is opening up about her much-needed career hiatus following the death of her friend and former co-star, Robin Williams.

While discussing her work with one of her favorite charities, This Is About Humanity, ahead of their big Aug. 27 gala in Los Angeles, Gellar reflected on the time she took a step back from her career to process the death of Williams.

"I've been working my entire life," she told PEOPLE exclusively. "When I had kids — and it was right after Robin passed away — there was just so much going on in my life and I just said, 'I need to take a break.'"

The 45-year-old actress played Williams' on screen daughter in the CBS sitcom The Crazy Ones from 2013-2014.

The series marked Williams' final television role before the actor died by suicide at age 63 on Aug. 11, 2014. It was later discovered Williams had Lewy body dementia, the second-most common type of progressive dementia after Alzheimer's disease.

Frazer Harrison/Getty; Ethan Miller/Getty Sarah Michelle Gellar and Robin Williams

Although their time on screen together was short lived, the Buffy the Vampire Slayer star shared an incredibly special bond with her TV dad — inspiring her to take some time to be home with her own children, daughter Charlotte Grace, 12, and son Rocky James, 9.

"I need to be here for these early formative years of my kids' life," shared the mom of two. "I needed that break to be the parent that I wanted to be."

But as her kids started to grow older, the wife of fellow actor Freddie Prinze Jr. realized something was lacking from her every day routine.

"I started to really miss it," Gellar recalled. "But it's also finding the right opportunity, something that speaks to you that also speaks to your audience."

Kevin Winter/Getty

RELATED: Sarah Michelle Gellar Is 'Honored' to See 'Buffy' 's LGBTQ Legacy: 'It Stands Up to the Test'

The right opportunity finally came knocking with the new Paramount+ drama series, Wolf Pack, where Gellar will star as arson investigator Kristin Ramsey. She is also set to executive produce the series.

"It's about working with people that I really love working with, where I look forward to spending time with the people," said Gellar, who had to travel to Atlanta to shoot the series. "I want everyone to have a good time because look, acting's fun. We're creative, and yeah, sometimes the nights are really long, but what we get to do is really cool."

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

While the I Know What You Did Last Summer star gets ready to return to the screen, one thing she refuses to ever take a hiatus from is her philanthropy work at the U.S.-Mexico border.

"My husband always jokes that I work as an actor to support my charity habit," Gellar said with a chuckle after returning from a bus trip with This Is About Humanity. "Because if I could donate every free moment I have, I would. But one of the things that I really like, and I look for specifically in the charities that I work with, it's sort of that direct connection. This Is About Humanity, there is no overhead. It all goes directly to the charity and you can actually physically see it."

Valorie Darling/TIAH

Gellar loves the work she does with the organization so much that she will be doing her best to take a break from filming in Atlanta to make the charity's upcoming gala.

"There was a trip we did a couple months ago to this incredible shelter in Tijuana," Gellar explained. "It's a YMCA shelter for unaccompanied minors, but specifically LGBTQ, which is very tricky in a Catholic culture like that. They have a little school room upstairs and the staircase to go up. It honestly felt like you were taking your life in your hands just walking up these steps."

"Gloria Calderon was on the trip, and she was like, 'We need to fix this,' and in two weeks she had raised enough money to fix the stairs and then we got to go down there and see the staircase," she added. "You really know not just where your money is going, but where your love is going."

Wolf Pack is expected to premiere on Paramount+ in late 2022.