Madera police officers stopped Lilliana Huerta in the area of B Street and 11th Street.
Police say Huerta had a blood alcohol level two times above the legal limit. Huerta's sister Lizett Huerta, and a man named Juan Cassarrubias were inside the car when officers stopped the vehicle.
Investigators also found a .25 caliber gun in the car.
Huerta was arrested on suspicion of DUI. Police also arrested Cassarubias. Both were booked into the Madera County Jail.