The California Highway Patrol says it happened on Avenue 7 near Firebaugh Boulevard in Madera County.
Officers say a driver was going east when she lost control of the Jeep, causing it to overturn.
37-year-old Cassandra Cedillo from Fresno was thrown from the vehicle.
Officers say she was not wearing a seat belt and was declared dead at the scene.
Flavin was taken to the hospital and is expected to survive. Another person in the vehicle was not hurt.
Officers say alcohol or drugs do not appear to be factors in the crash.