Updated Story (8/19/19): Bethanie Carriker pleaded guilty to two counts of aggravated child neglect in a Blount County courtroom on Monday.

She was sentenced to 25 years in prison after a drowning incident left her 15-month-old daughter dead and her 26-day-old infant daughter fighting for her life back in May.

RELATED: BCSO: Infant found unresponsive in Seymour home bathtub released from hospital

The incident happened at their Seymour home on May 7. The infant was released from the hospital after being treated for her injuries for about a week.

Carriker had placed both children in a bathtub filled with about six inches of water and then left them there for a minimum of 10-15 minutes, authorities said during court proceedings. 

She must serve at least 85 percent of the 25-year sentence.

Updated Story (6/18/19): Bethanie Carriker was back in court on Tuesday after a drowning incident left her 15-month-old daughter dead and her 26-day-old infant daughter fighting for her life.

The incident happened at their Seymour home on May 7. The infant was released from the hospital after being treated for her injuries for about a week.

The hearing was short and a judge set a new hearing for August. Carriker's husband Matthew was in the courtroom Tuesday.

The search warrant states that Carriker and her husband had a domestic argument on the morning of the incident and law enforcement was called. The children were found unresponsive later that day.

RELATED: BCSO: Infant found unresponsive in Seymour home bathtub released from hospital

Carriker has been charged with aggravated neglect, according to officials.

Original Story (6/5/19): Blount County authorities found evidence last month that one or both of the children reported having been found unresponsive in a bathtub in Seymour were possibly given Benadryl, a search warrant states.

The 15-month-old and 26-day-old were in the care of their mother, Bethanie Carriker, at the time of the May 7 incident. Benadryl is an antihistamine used to treat allergies that can cause drowsiness.

The incident left the 15-month-old dead and the 26-day-old infant fighting for her life.

According to a spokesperson from the Blount County Sheriff's Office, the infant girl was released from the hospital roughly a week later. 

RELATED: BCSO: Infant found unresponsive in Seymour home bathtub released from hospital

The search warrant also states that Carriker and her husband had a domestic argument on the morning of May 7, and law enforcement was called.

Carriker's husband, Matthew, left for a cool down period.

Later, Carriker sent "multiple" messages and communications to him including a photo of one of the children to get him to come back home a few hours before the children were found unresponsive, according to the warrant.

Investigators want to use evidence on Carriker's cell phone, but her public defender has asked the state to preserve all data from her cellphone. The search warrant addresses access to Carriker's phone.

The warrant said the "affiant believes that it is more probable than not that this I-Phone belonging to Bethanie Carriker contains valuable evidence of aggravated child neglect and criminal homicide."

Carriker's husband was concerned May 7 about Bethanie Carriker "potentially causing harm to (the children)..." the warrant states.

The warrant doesn't detail why authorities suspected the children may have been given Benadryl.

When authorities arrived at the Carriker home, they found her giving the children CPR, according to the Blount County Sheriff's Office. She said she'd found them unresponsive in the water after leaving them for some 10 minutes.

"Evidence observed at the scene ... seemed inconsistent with the story given by Bethanie Carriker," the warrant states. "This included the location of the baby baths as well as baby bottles."

A notation on the return of the warrant dated May 13 says the search warrant was "served but not executed. New search warrant to follow. Nothing taken."

RELATED: Lawyers want to preserve mother's cellphone data in case of infant bathtub drowning

Carriker is charged with aggravated neglect, according to officials.

She faces a June 18 court hearing in Blount County.