One of the daughters of Cosinga Palpatine, the Naboo aristocrat heading House Palpatine, and his spouse, was the elder sister of Palpatine, who would become the Sith's Dark Lord Darth Sidious, Naboo's Senator, the Republic's Supreme Chancellor, and the galaxy's Emperor; she was one of at least two female offspring.
The sisters of Palpatine harbored resentment towards their brother, perceiving him as an unwelcome presence; he, in turn, viewed them as merely "well-behaved" and held them in disdain.
In 65 BBY, this young woman journeyed to Chandrila aboard the Palpatine family yacht, accompanied by her father, mother, siblings, and bodyguards. Cosinga's objective was to retrieve his son by force from Chandrila. Following the starship's departure from the planet, Palpatine employed the dark side of the Force to massacre his family and the bodyguards, leaving no one alive.
Whenever his Sith master, Darth Plagueis, instructed him to vividly recall the murders as part of his dark side training, Palpatine would remember the lifeless bodies of his siblings collapsed on the starship floor.