Michelle Carter is scheduled to appear in court Monday when prosecutors' request that she begin serving her 15-month sentence will be considered.
Carter was convicted in 2017 of involuntary manslaughter for her role in the death of Conrad Roy III. A judge allowed Carter to remain free while she appealed in state court.
Massachusetts' highest court upheld her conviction last week.
The courts found Carter caused Roy's death when she instructed him to get back in his truck as it filled with toxic gas.
Her lawyers say she isn't responsible for Roy's suicide. They said in an emergency motion filed Monday that her sentence should be further delayed.
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