The actress's mom passed away on Thursday morning in Los Angeles

Credit: Kevin Winter/Getty

Julia Roberts‘s beloved mom, Betty Lou Bredemus, 80, has died PEOPLE has learned. The actress’s mother had been suffering from lung cancer.

She passed away early Thursday morning in Los Angeles.

Bredemus, who once ran an acting school in Smyrna, Georgia, was the mom of four children – Eric Roberts, 58; Julia, 47; Lisa Gillan, 49, and Nancy Motes, who died last year at age 37. She was also the grandmother of actress Emma Roberts, Eric’s daughter, along with Julia’s children – twins Phinnaeus and Hazel, both 10, and Henry, 7.

Julia opened up about how she first realized she had become a celebrity when she went to go see a film with her mom shortly after starring in 1988’s Mystic Pizza.

“The first time I felt famous was when I went to the movies with my mom,” Julia told PEOPLE in 2002, noting that another theatergoer had recognized the actress from her breakout role.

Julia has been in Los Angeles filming her new movie The Secret In Their Eyes.