BROWNSVILLE, TEXAS -- Brownsville police had a strange case on their hands Monday.

They arrested a grandmother accused of driving drunk with her 2-year-old grandchild in the back seat of the car.

Police said 52-year-old Maria Dolores Ruiz was weaving in and out of traffic on Boca Chica Boulevard when another driver noticed Ruiz almost falling asleep at the wheel.

Police said the man called 911, made Ruiz pull over into a parking lot and waited until they arrived.

"She was highly intoxicated," said Brownsville Sgt. Jimmy Manrrique.  "She couldn't do a field sobriety test, and at that point, she was arrested for driving while intoxicated."

Ruiz was also charged with endangering a child.

The child was unharmed and taken to his mother.