Jennifer Garner didn’t have to go far when researching her role in hr latest film, Family Switch. 

Speaking exclusively to PEOPLE at the premiere of the movie in Los Angeles on Wednesday, the 51-year-old actress admitted that she couldn’t help but ask “a bunch of questions” to her three children before preparing to play a teenager in the Netflix comedy.

“You’re turning the volume up so much because it’s all so exaggerated,” says Garner, who shares daughters Violet Anne, 17,  and Seraphina Rose, 13, as well as son Samuel Garner, 11, with ex-husband Ben Affleck, 51. “But yes, I definitely went to my teens and asked a bunch of questions. They were all like, ‘Mom, you’re crazy.’ “

In Family Switch, Garner is part of a household who, after chance encounter with an astrological reader (Rita Moreno), wakes up to realize they’ve all swapped bodies.

Garner plays a mom who is suddenly in the body of her teen daughter (Wednesday‘s Emma Myers), while her husband (The Office‘s Ed Helms) and her son (Brady Noon, of Good Boys fame) have switched bodies. Even her infant son (actors Theodore and Lincoln Sykes) and her dog are caught up in the fun.

Jennifer Garner pictured with her children Violet, Seraphina and Samuel in 2018.ROBYN BECK/AFP VIA GETTY

Things are much less hectic off-screen for Garner at home. Asked about the chaos of life as a mom of three, Garner tells PEOPLE, “My kids are funny and they’re smart, and they work really hard. And their teenage antics are at the very lowest, G-rated level, so I’m doing okay.”

However, despite her kids’ humor, intelligence and work ethic, the mother-of-three would not like to trade places with them.

“You know what? I think my kids work so hard, and they have so much pressure on them that I could never even have imagined as a teenager myself,” Garner told PEOPLE in this week’s issue. “I’ll stay right here in my old lady body, thank you very much.”

From Left: Emma Myers as CC, Brady Noon as Wyatt, Jennifer Garner as Jess Walker and Ed Helms as Bill Walker in Family Switch.COLLEEN HAYES/NETFLIX

The star’s eldest child Violet is also set to go to college soon. Speaking to PEOPLE at the premiere of Family Switch, Garner explains that although “it hasn’t really sunk in” she does sometimes  “have moments where it hits me.”

“But so far, I’m just excited for her,” she adds.

On Tuesday, Garner appeared on Live with Kelly & Mark where she opened up about Violet touring colleges. While the 13 Going on 30 star admitted that she could “see the stress,” she also stated that her daughter has been “handling it like a champ and she’s totally in charge.”

“I am. I’m about to have an adult,” Garner gushed. “Three days. I’m three days from my eldest turning 18. Can you guys believe that?”

Family Switch starts streaming on Netflix on Dec. 30.