JULIA ROBERTS is outraged that her niece, Emma Roberts, got engaged to actor Evan Peters and is begging the Hollywood wild child to call it off, a source says.

“Emma’s only 22, and Julia thinks she’s making a big mistake by rushing into things with Evan,” said a family insider.

“Julia is sure it will only lead to pain and heartbreak. She told Emma, ‘You’re too young to get married. You don’t know what you’re doing.’”

And Aunt Julia should know The “Pretty Woman” beauty was just 23 in 1991 when she called off her $300,000 wedding to “Flatliners” co-star Kiefer Sutherland, 24, just days before the nuptials.

“Getting married at this time in my life would’ve been the biggest mistake ever,” said Julia, who’s now starring in “August: Osage County.”

Emma began dating Peters, 26, her co-star in the hit FX series “American Horror Story: Coven,” in the spring of 2012. They reportedly got engaged over the holidays when he proposed with a pink gold and diamond ring.

The couple made headlines in July when “Nancy Drew” cutie Emma was arrested for reportedly attacking Peters during a fight at a Montreal hotel.

As The ENQUIRER reported, Julia “called an emergency family meeting” after the arrest to discuss Emma’s out-of-control behavior.

“Emma thought Julia was overreacting then, and that she’s overreacting now,” said the source.

“Emma’s convinced she did the right thing by accepting Evan’s proposal and she feels that Julia should just butt out!”