Supermodel Niki Taylor, who was critically injured in a car accident early Sunday morning in Atlanta, underwent several hours of surgery on Thursday and remained in critical condition with severe liver and abdominal injuries, said a spokeswoman for Atlanta's Grady Memorial Hospital. "She's out of surgery," said Denise Simpson. "She's critical." Doctors began operating on the 26-year-old model early Thursday. Taylor has been hospitalized since Sunday when the Nissan Maxima she was riding in crashed into a utility pole. The driver of the car, Chad Renegar, said that the accident occurred as he was reaching down to grab his ringing cell phone. (He and another passenger were treated for only minor injuries and released after the accident.) Taylor, who wearing her seat belt, initially did not seem to be hurt. Later she was found to have sustained severe injuries to her liver and abdomen. Doctors have said it may be weeks before they can assess how well or even whether or not Taylor will recover. "She has a strong will and the drive to overcome this," her former father-in-law, Reynel Martinez, 54, told PEOPLE. "We'll pray for her. That's all we can do now."