New Delhi, Feb 20 (ANI): Julia Roberts' mother Betty Lou Motes has died at the age of 80 after struggling with lung cancer. The 'Notting Hill' actress' mother, who was living with her daughter, son-in-law and their children, was reportedly battling with her disease at St. John's Health Center in Santa Monica, California, an online portal reported. According to reports, doctors found a tumour on Motes' lung during an MRI scan in 2013, and revealed it months after. The actress' half sister Nancy Motes was found drowned last year by her fiance John Dilbeck after a drug overdose in Los Angeles.