|“||Only idiots aren’t scared of things that are scary.||”|
– Taryn Duarte, The Cruel Prince
Taryn Duarte is Jude’s twin sister.
Due to the fact that in The Cruel Prince it is implied that Taryn and Jude are identical twins, it is safe to assume that Taryn also has red-brown hair describe to be the color of a willow tree, like her twin, as well as softer features in comparison to the fae, such as her heart-shaped face.
Unlike Jude, Taryn doesn't like the idea of challenging the folk, as she believes that they are more likely to ignore her if she does the same to them. Taryn also wishes to fall in love with a fey and marry him in order to join the court, and doesn't mind being treated unfairly or tested by her lover since she believes that "they don't love the same way humans do".
While Jude craves power and--to a deeper yet more subtle extent--acceptance, Taryn's motivations are more unclear. She is outwardly more meek and submissive than Jude; part of her resents her twin for drawing so much negative attention to them. However, as shown by her actions in the end of The Cruel Prince, Taryn can be just as manipulative and ruthless in securing her place in Faerie; the two sisters just go about doing this in different ways.
During her childhood, Jude and Taryn (as the only humans) are targeted by the other faerie children (in particular Cardan, Nicasia, and Valerian). She witnesses Jude and Cardan's growing feud, which eventually culminates in Jude nearly drowning when she refuses to withdraw from the Summer Tournament. Cardan forces Taryn to kiss him in order to prove that she should not be held accountable for Jude's defiance. Later, Jude shoves Cardan when she finds her crying when he is talking to her. Taryn insists that what she was crying about was not Jude, and begs her to not fight Cardan in the Summer Tournament.
The night of Dain's coronation, Taryn reveals that she is engaged, but won't say to whom. At the coronation, she sees Balekin and Madoc betray Dain and kill Eldred, his consort and his children except for Balekin and Cardan, who didn't attend the ball. When the ball is finished, Taryn presumably goes back to Madoc's Estate with her betrothed. When Jude comes home, it is revealed that her betrothed is Locke, and he was playing them against each other the whole time. Jude challenges Taryn to a duel, which is broken up by Vivi, who glamours them to stop fighting. Later, Madoc gives his blessing for their marriage, although he has his misgivings. Taryn refuses to speak to Jude after the duel.
In The Wicked King, Taryn tries to make amends with her twin sister, Jude, before her wedding. Jude reluctantly rekindles her relationship with her sister after reminiscing all the hardships they've been together, and that there was no time to ruin their relationship after a few arguments. Taryn proceeds to design clothing for Jude. Near the end of The Wicked King, Taryn is revealed to be working with Madoc after she impersonated Jude in front of a sick Cardan. She gets Cardan to give up half his army and also gets him to sever Madoc's ties to the Blood Crown.
Main article: Jude and Taryn
At first, Jude and Taryn have a very close relationship, with Jude telling her sister everything and Taryn growing more and more worried about Jude's safety. However, as the events of The Cruel Prince unfold, Taryn starts to show some resentment towards her sister, and it soon becomes clear that she might not care for Jude's feelings as much as Jude cares for hers. Taryn refuses to speak to Jude for the remainder of The Cruel Prince. In The Wicked King, Taryn makes amends with Jude, and they resume their relationship. It is clear that, although Taryn does help Jude in various ways, she is very manipulative, often asking Jude for favours while promising nothing in return. Later, Taryn betrays Jude and impersonates her in front of Cardan, taking half of his army for Madoc and severing Madoc's ties to the crown.
Main article: Locke and Taryn
Locke is the Taryn's secret lover for the most part of The Cruel Prince, before becoming engaged. However despite this, he still became Jude's lover much to Taryn’s knowledge. Later on, Taryn confesses she hated that Locke messed around with Jude, but her distaste was more focused on her sister. Even after everything Locke has done to the both of them, Taryn continues to choose Locke instead of siding with her sister, saying that Jude never cared for Locke and that he was just another thing to take from Cardan. Taryn eventually chooses to get married with Locke, receiving Madoc's blessing.
In The Cruel Prince, Madoc seems to have a closer relationship with Jude, because of their shared ruthlessness and lust for power. However, in The Wicked King, Taryn and Madoc conspire against Jude to accomplish their own ends.
- Taryn is the older twin.
- She has some Latinx ancestry in her background, through her dad's family. 
- Like Jude, her skin color, and full race/ethnicity have not been confirmed by the author.