Rebecca Johnson, 29, was convicted of second-degree murder for planning the robbery that led to the death of Carrie Smith.
The jury also convicted Rogel Suero, 31, of Allentown, who police say carried out the robbery, which netted $35,000. Suero also was found guilty of second-degree murder.
Smith, 76, of Wilson, suffered a fatal heart attack last March following the robbery in January at her home on Hillside Avenue.
The Morning Call says Northampton County jurors deliberated for four hours Monday before convicting Johnson and Suero.
Under state law, a second -egree murder conviction carries an automatic life prison sentence.
Police have said Johnson set up the burglary, stealing a key and making sure her cousin, who lived with Smith, was out of the house.
Suero and an accomplice -- who has yet to be identified -- allegedly woke Smith up, threatened her, put a pillowcase over her head, and took cash and jewelry from her safe.
She died two months later, and the county coroner ruled her death a homicide since it resulted from the heart attack that resulted from the robbery.
The Express-Times says Suero testified last week that he had never met Smith and had nothing to do with the robbery, although he couldn't recall where he was that night.