Jennifer Garner is relieved she's not a teenager now.

Jennifer Garner is glad she's not a teenager

Jennifer Garner is glad she's not a teenager

The 51-year-old actress - who has Violet, 17, Seraphina, 13, and 11-year-old Samuel with ex-husband Ben Affleck - is happy in her "old lady body" because she sees how much "pressure" her own kids are under.

She told People magazine: "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.

"I’ll stay right here in my old lady body, thank you very much."

Despite juggling the needs of three children, Jennifer knows things could be more more difficult as a parent because her brood thankfully don't cause too much disruption with their "teenage antics".

She said: “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.”

The former 'Alias' star's latest movie, 'Family Switch' sees her character accidentally swap bodies with her teenage daughter and Jennifer admitted she had a "bunch of questions" for her own family to help her prepare.

She said: “You're turning the volume up so much because it's all so exaggerated.

“But yes, I definitely went to my teens and asked a bunch of questions. They were all like, 'Mom, you're crazy.' "

The '13 Going On 30' actress' eldest child turns 18 this week and is preparing to go off to college soon, something Jennifer admitted "hasn't really sunk in" yet.

She added: "I have moments where it hits me.

“But so far, I'm just excited for her."