Following the disappearance of several of her relatives, she was kidnapped by her master's son in 1765, but rescued in due time by the Assassin Aveline de Grandpré. With the aid of Madeleine de L'Isle, Thérèse was escorted out of New Orleans and, unbeknownst to Aveline, to the labor camp of Chichen Itza, where she was put to work.
In 1769, Thérèse met Aveline again, when the latter traveled to Chichen Itza, attempting to find out the extent of the Templars' plans. Despite Aveline's suspicions, Thérèse appeared to be perfectly happy in the work camp, claiming it was a wonderful community where she had found freedom. However, upon further questioning, she revealed the people technically didn't own the land and hinted that they weren't allowed to leave, with the ones that tried to escape facing punishment.
- According to Assassin's Creed Initiates, Thérèse was visibly pregnant at the time of her rescue by Aveline, though there was no evidence of this in the game itself.