Diane Duey said that her daughter and Xavier were in the habit of grabbing a pizza at the Runway 32 Pizzeria at the Mission Valley shopping center, where police found the car.
''About once a week Jennifer would bring home a pizza from there," said Diane Duey. "They've been known to get a pizza there on the way home."
Duey's mother said she believes it's highly unlikely that the women stopped at a bar before they might have driven to the pizza parlor. They were both under 21, and not "the type to hang out somewhere like that," she said.
''Besides, friends have confirmed that they just didn't drink alcohol. And I can tell you that it would be more like them to get a movie to go home and watch on the VCR and pick up a pizza," said Diane Duey. "Stopping off somewhere like that just isn't the type of thing they would do."
But Diane Duey said she can't figure out where they could have gone after leaving the 7-Eleven, if they didn't go to the pizzeria.
Ray Barsanti, owner of the Mission Valley Inn, said he saw Xavier 's car in the shopping center about 11:15 p.m. Saturday.
But Steve Zensius, 16, who works at Runway 32 Pizzeria, said the white convertible was not parked behind the Chevron station when he left work at 11:20 Saturday night. He said he would have noticed because he was familiar with the car and both victims.
Zensius said police on Sunday showed him three photographs of clothing allegedly belonging to the women. One photo was of a long, pink coat; another was of a long, perhaps knee-length black coat and white scarf; and another was of a red, black and gray checked shirt.