Westchester County Police are still investigating what caused her car to leave the parkway at about 8:30 p.m. just north of the Roaring Brook Road exit.
Police said Sanchez was ejected when he car rolled over. She was not wearing a seat belt while driving north with her two children, ages 12 and 13. The children were wearing seat belts and were treated for minor injuries, police said.
Sanchez was taken to Northern Westchester Hospital, where she was pronounced dead, police said.
Her children also were taken to Northern Westchester Hospital, where they were treated for bumps and bruises, police said.
It appears that Sanchez may have fallen asleep while driving, police said.
The parkway was initially closed in both directions, and the northbound lanes remained closed between Roaring Brook Road and Route 133 until about 5:40 a.m.
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