A Cobb County woman pleaded guilty Wednesday to stabbing her sister to death with a steak knife and was sentenced to life in prison, according to the county's district attorney.

Chakaya Brittney Folborg, 24, admitted this week that she killed her sister, Kourtney Chanel Dyches, at their family’s Mableton home on Feb. 20, 2012, as part of a plea deal, DA Victor Reynolds said. The case had been set to go to trial next Monday.

“This victim was a vibrant young lady with the rest of her life ahead of her,” Sherwin Figueroa, assistant district attorney, said in an emailed statement. “The defendant, without any provocation, took a knife from the kitchen some two hours before the killing and waited until the victim was in the shower before viciously stabbing her at least six times.”

Both sisters were 21 at the time of the stabbing, according to police. Folborg was adopted into the family as an infant, Reynolds’ office said.

The morning after the killing, investigators said a dispute between the sisters led to the stabbing, which happened with other family members in the home. Dyches was dead when officers arrived, police said.

Folborg turned herself in to police several hours after stabbing her sister. She has been held in the Cobb County jail without bond since her arrest.

Superior Court Judge S. Lark Ingram sentenced Folborg to life in prison. She will be eligible for parole after serving 30 years, the DA said.