Kimberly Suzanna Dolan, 21, argued with the 50-year-old mother outside the Allegheny County’s Prospect Terrace apartments at about 8:45 p.m.
The women were outside because a fire alarm had been set off in the building. The mother told Dolan she wasn’t going to fight with a child and Dolan left, police said.
The mother called her adult daughters, who are 29 and 26, and told them about the argument. Dolan came back and stabbed the 29-year-old 10 times in various places, according to the criminal complaint filed against Dolan.
The 26-year-old tried to intervene and was stabbed three times and her mother also attempted to stop Dolan and was stabbed twice, according to the complaint.
A bystander who wasn’t named by police knocked Dolan to the ground and dislodged the knife from her hand, police said.
Dolan drove away but was stopped by police shortly thereafter, police said.
All of the women were treated for injuries at local hospitals, police said.
The 29-year-old is in critical condition, and the 26-year-old and her mother are in stable condition in the hospital, police said.
Dolan was treated and then taken to Allegheny County Jail. She is charged with three counts each of aggravated assault, simple assault, and recklessly endangering.
An attorney wasn’t listed for Dolan in online court records.