Melissa Gorga and Teresa Giudice attend Svedka Vodka's celebration of National Walk Of Shame Day at Yotel on July 27, 2011 in New York City. Credit: Astrid Stawiarz/

Melissa Gorga performed to a crowd of 10,000 on Sunday's Real Housewives of New Jersey during a concert appearance at New York City's Beatstock music festival, but two of her closest family members -- nieces Gia and Milania Giudice -- weren't even sure the mom of three could pull it off.

"Melissa stinks!" sniped Teresa Giudice's daughter Milania as she and her sister debated whether their aunt would perform her single, "Rockstar," live rather than lip-synch. In the end, Gorga, 32, wowed the Beatstock crowd -- and won raves from her sister-in-law, Teresa, 40.

"I never knew Melissa was a really good dancer and I'm actually happy to support her," the Giudice family matriarch said after Gorga took the stage, coached by Jennifer Lopez's choreographer ex, Cris Judd.

Giudice's performance compliments were just the beginning of the sisters-in-law's attempt to make nice before taking off on their family road trip to Napa Valley, Calif.  

"Teresa and I are trying to build our relationship. We're 100 percent better and I think I like it," Gorga admitted of Giudice, who previously made a habit of slamming the Gorga family even after attending a therapy session with her brother, Joe Gorga.

As their Napa trip approaches, Giudice appears to have shifted her focus from foes Caroline Manzo and Jacqueline Laurita to the Gorgas -- in a positive way. "This trip is not about Jacqueline and Caroline," she reasoned. "This trip is about going away with my brother, and Melissa and Joe and I having the fun times we used to have."

Tell Us: What do you think of Melissa's singing?