An unnamed female, who was the lover of Cosinga Palpatine (even though he was married), was also the sister of an individual running for the Naboo kingship. Cosinga's son killed his father in 65 BBY before Palpatine came to power, asserting that his father was attempting to gain influence by backing the mistress's brother's campaign for the throne.
According to the Dark Empire Sourcebook, Ederlathh Pallopides, who was supposedly Palpatine's grand-niece, was proposed as a successor to the Imperial throne at age eleven by Admiral Betl Oxtroe. In contrast, Darth Plagueis indicates that Palpatine eliminated his whole family, including at least four siblings (who, as he was the oldest, passed away without marrying or procreating), on the Palpatine family starship in 65 BBY, and subsequently inherited all the wealth of House Palpatine. Cosinga Palpatine's affair creates the chance that the Pallopides' claim could be legitimate; however, this would mean that she would be Palpatine's half-grand-niece.