Andrea Balcer, 20, had been convicted of stabbing her parents, Alice and Antonio Balcer, on Halloween morning in 2016.
Born a male and formerly called Andrew, Balcer now identifies as female and prefers to be called Andrea.
Minutes after killing her parents, prosecutors said, Balcer called 911 and told a police dispatcher she just snapped.
Prosecutors said that Balcer later confessed that she planned to kill her parents.
Defense attorney Walt McKee said Balcer thought her parents would not be supportive of her transition to become Andrea Balcer and that is why she killed them.
Balcer also pleaded guilty to killing the family dog so it wouldn't bark while she killed her parents.
Balcer's older brother, who was spared that morning, said their parents were loving and supportive.
Balcer, who was a teen at the time of the murders, pleaded guilty under an agreement that caps her sentence at a maximum of 55 years.