CHANDLER, Ariz. -- The mother of a toddler who is on life support with a fractured skull has been arrested in connection with the child's injury.

Josefa Talavera, 20, was booked into jail Wednesday on a charge of failure to protect a child, a Class 2 felony under the child abuse statutes.

Chandler police said they had learned Talavera was present when her boyfriend, Jeramias Aguilar, allegedly threw her 2-year-old daughter to the floor on June 6. They said the mother did not call 911 for help for at least two hours after the incident.

The girl was unresponsive when police and paramedics arrived, police said. She was still on life support Thursday.

Aguilar, 21, was booked June 6 on a charge of felony child abuse. Police said he was in the country illegally.

Police said Aguilar told investigators he picked up the baby and threw her down on the concrete floor because she would not stop crying.