Thais was born after midnight on November 23. She was raised by her father, Michel Allard, in Welsford, Connecticut until he died in a car accident. Thais follows the rules and rarely parties. She went to live in New Orleans with Axelle Gauvin until she found out she had a twin, Clio. She then moved in with Petra Martin, her grandmother, and Clio where Petra began to teach Thais witchcraft. At the beginning of the book series, she began to date Luc-Andre Martin and later found out he was also dating Clio at the same time. Thais was hurt by this and so began to date a boy named Kevin LaTour but broke up with him in the final book. In the end, she gets back together with Luc.
Thais is a Sagittarius and her element is water. She is also a powerful witch like her sister and sometimes when she is in danger, spells will pop into her head. Thais has a fleur-de-lis birthmark on her right cheek-- Clio also has one, on the left.She and her sister both are identical to Cerise Martin, their ancestor, except they have black hair, like Melita Martin.