It happened last night around 8:40pm in the 1400 block of East Bayshore, less than a block from her house.
The Galveston County Sheriff's Office says the driver that struck the child didn't see her until the last second and couldn't avoid the impact. Authorities say he spotted a deputy just down the street and flagged the officer down for help.
The toddler was unresponsive when she was airlifted to University of Texas Medical Branch Hospital where she died.
The driver provided a blood sample to authorities.
The GCSO says the mother put the toddler child in her crib for the night, and then walked out of the room and went to the bathroom for a brief time. She says was not aware of her child missing until the deputies knocked on her door.
No charges were filed, but the incident is still being investigated.