There she was in her cowboy hat and crocheted mini, posing alongside none other than Taylor Swift at Coachella in Indio, California, on April 13.

“Two absolute QUEENS,” Luis Ruelas captioned a shot of his wife, Teresa Giudice, on Instagram. The Real Housewives of New Jersey star’s unlikely festival pal wasn’t the only thing that surprised fans.

Among the 550-plus comments was plenty of speculation about what the 51-year-old had done to maintain her youthful looks. “How do her lips keep getting bigger,” pondered one poster.

“Teresa appears to have recent lip filler injections as her lips look quite puffy and plump,” Michigan-based plastic surgeon Anthony Youn, M.D., F.A.C.S. exclusively tells Life & Style, who does not treat the star, adding that filler in her cheeks and smile lines could make her face appear more round. Over the years, Tre has copped to multiple surgeries, from a 2008 breast augmentation to a nose job, fillers and a nonsurgical facelift.

Board certified Beverly Hills plastic surgeon Dan Yamini doesn’t question what the mom of four has admitted to (she is not his patient), but speculates she could have done more. “If she’s had any secret plastic surgery done, most likely it would be a combination of brow lift, midface, lower face and neck lift,” he says, which would explain why there’s no sagging. “Either way, she’s aging beautifully.”