It’s been almost three years since Caitlyn Jenner made her public debut as a trans woman. Since then, the reality star has confessed how thrilling it is to experience life as a female after spending her first 65 years as a man. "In so many ways," she’s said, "I feel like I’m a teenage girl discovering herself!"

Lately, that’s exactly how she’s been acting. Caitlyn, 68, is fixated on turning back time, whether through her style choices or hanging with gal pals a quarter her age. "Caitlyn is obsessed with her looks and all things glam,” an insider exclusively told Life & Style. "She keeps up with fashion on Instagram and always, always gets her dresses shortened!"

Cait’s constantly making tweaks to her appearance — some more serious than others. As part of her transition, she had 10-hour facial feminization surgery, a breast augmentation, and gender reassignment. But the diva also "feels like she should look like she’s in high school," said the insider, who added that Caitlyn had her ears pinned back. So she’s getting regular Botox, fillers, and skin treatments to maintain a youthful appearance.

She’s sure maintaining a youthful inner circle. When not hanging with daughter Kylie, 20, and her pals, Cait’s constant companion is Pepperdine University student Sophia Hutchins, 21. "It’s like she’s hoping Sophia’s youth rubs off on her," added the insider. It’s Caitlyn’s way of making up for lost time. "For men and women who have undergone a transition [later in life], it’s not uncommon to start acting younger," said psychologist Dr. Julie Armstrong, who hasn’t treated the star, "to [catch] up on social experiences they missed out on earlier."

The only problem? She’s adopted the attitude of a teen, too! "She has become so catty," the insider insisted. "Bruce was the nicest, but Caitlyn acts like she thinks she’s in Mean Girls!" Ouch!