The timely intervention of a teenage girl saved the life of her 8-year-old sister. She stopped her mother, who allegedly drowned her 6-year-old child, from killing the girl.

Jamie Bradley Brun, 37, was arrested after the alleged attack on her daughters. Deputies from the Beaufort County Sheriff's Office went to a South Carolina home early morning Friday.

Officers learned that Brun's 16-year-old daughter was inside the house when the mother killed her 6-year-old daughter and then tried to drown the 8-year-old girl, reported AP News. Details about how Brun tried to drown the child were not clear.

The teenage daughter woke up to her 8-year-old sister's screams coming from the bathroom. The teenager sprung into action and rushed to the bathroom in time to save the younger child.

The teenager then ran to a family member's house nearby. A 911 call was made to inform the sheriff's office about the woman trying to drown her child.

"I'm very proud of her. I think she did an unbelievable job. She defended her family when no one else was available," Beaufort County Sheriff P.J. Tanner said about the teenager. "Her courage is amazing."

Deputies arrived at the scene and found Brun, as well as the body of the 6-year-old, identified as Mackaya Bradley-Brun.

"The early morning investigation revealed that Jamie Michele Bradley-Brun most likely drowned the 6-year-old. Following that Bradley-Brun then attempted to drown an 8-year-old child," the sheriff's office said in a statement. "A plea for help from the eight-year-old woke others in the home who were able to intervene and call 911 for help."

During her arrest, Brun tried to get hold of a deputy's gun but was subdued using a Taser. She was taken into custody and is facing charges of murder and attempted murder, Cleveland 19 News reported.

It's not clear why the mother wanted her children dead.

"I'm not a mental health expert. It's not my job to determine if someone has a mental health problem," Tanner said.

Family members are now taking care of the teenage daughter and the 8-year-old girl, who did not appear to be seriously injured.

Brun reportedly had no previous records of criminal conduct. Records only show that officers were once called to her home after a school employee expressed concerns about one of the children's mental health a couple of years back, the sheriff said.

"There is a lot more information that we have and a lot more details that we know but at this point, we can't share," Tanner added.

Representational image of a man in handcuffs. Kevork Djansezian/Getty Images