A San Benito mother is being questioned by police following the death of her 4-month-old baby.

Baby Kimberly Nicolas died on Sunday night after spending several days on life support at the Valley Baptist Medical Center in Harlingen.

Action 4 News first reported on the arrest of the baby's teenage aunt, Ada Marlene Rodriguez, last week.

Investigators said the baby girl was rushed to the hospital after being found face down in a car seat.

Baby Kimberly's mother claims she gave the 4-month-old girl to Rodriguez in a carseat while she dropped her child and their other sister's child off at school.

Rodriguez claims she was asleep and didn't know she was supposed to watch her niece but police allege Baby Kimberly couldn't have turned over by herself in the constraints of the carseat.

The 17-year-old aunt is being held at the Cameron County Jail under an immigration detainer and a $100,000 dollar bond for injury to a child.

San Benito Police Lt. Martin Morales told Action 4 News that Baby Kimberly's death has opened another round of investigations.

Morales said police are questioning the girl's mother, Luz Esmeralda Nicolas, again.

Police are waiting on autopsy results before deciding if charges against Rodriguez will be changed.

There was no word on funeral arrangements for Baby Kimberly as of Tuesday morning.