No she didn’t, the lid was not put on and it spilled when they handed it to her from the drive through window.
Yes, she did. She was a passenger, riding with a relative, they pulled away from the drive-through, and parked in a parking spot. She pulled the lid off (pulling toward herself) to doctor the coffee while she was holding it in her lap. It was 100% her fault.
On February 27, 1992, Stella Liebeck, a 79-year-old woman from Albuquerque, New Mexico, ordered a 49-cent cup of coffee from the drive-through window of a local McDonald's restaurant located at 5001 Gibson Boulevard Southeast. Liebeck was in the passenger's seat of her grandson's 1989 Ford Probe, which did not have cup holders, and her grandson Chris parked the car so that Liebeck could add cream and sugar to her coffee. Liebeck placed the coffee cup between her knees and pulled the far side of the lid toward her to remove it. In the process, she spilled the entire cup of coffee on her lap.[9] Liebeck was wearing cotton sweatpants; they absorbed the coffee and held it against her skin, scalding her thighs, buttocks, and groin.[10]