Authorities say Trinh Nguyen, 40, shot and killed both of her sons -- 9-year-old Nelson Tini and 13-year-old Jeffrey Tini -- inside their home back on May 2, 2022.
Nguyen also attempted to shoot a neighbor, but the gun failed to fire.
2 brothers die after being shot inside Bucks County home; mother charged
She then reportedly fled to New Jersey to obtain narcotics, which authorities say she ingested in an attempt to kill herself. She was later found inside her minivan at the United Methodist Church in Washington's Crossing and taken into custody.
A note found inside the car read: "Please call 911! My children are Dead in their bed at 119 Timber Ridge Rd 18940."
In other writings left for police, Nguyen blamed others for the problems in her life, which included the imminent eviction from her home where she was living.
Community honors Bucks Co. brothers allegedly shot by mother
On Wednesday, Nguyen pleaded guilty to two counts of first-degree murder, one count of attempted murder and related charges.
Judge Raymond McHugh sentenced Nguyen to two life terms without the possibility of parole for killing her boys and a maximum sentence of 10 to 20 years for the attempted murder of the neighbor, who was a cousin to Jeffrey and Nelson Tini.
Authorities say Nguyen planned the killing at least a week earlier, leaving a handwritten will that instructed the recipient of what to do with her and her sons' remains.