The Esther story
This girl is named Esther, and not for no reason. She is very similar to her Biblical namesake. Like the book of Esther, this Esther also features a young Jewish girl who is sent away from her Jewish community to be married, except this Esther doesn't go to her husband; she escapes to the New World instead. But, still, both women are isolated from their Jewish culture and are made to suffer because of misogyny.
The symbolic Anusim
The Anusim Jews are Jews who were terrorized by the Spanish during the infamous Catholic inquisition. In those days, they were still practicing their faith with more rites and religious rituals, but the Spanish Inquisition forced them to be less obvious. That is why for Esther, her Anusim background is symbolic, because like her parents, she too hides much about herself under threat of mistreatment.
The motif of story-telling
According to her Jewish culture, Esther knows the value of a good story. She tells stories like the Midrash, recapturing motifs and legends in modern tales that she invents on the spot, not unlike a jazz musician. She is a story-teller, and her stories are about resilience, honor, and the power of knowing the truth and not being dissuaded by one's broken culture. In her stories, the purpose of heroism is to help the community, not to punish it for its problems.
The androgyne
Because she was a teenage girl who managed to pass as a teenage boy, we know by inference that Esther is an androgynous person, and the idea to hide from trouble by disguising oneself as a boy is a common literary motif all over the world. Sometimes, androgyny is a sign of religious mysticism, so perhaps this novelist was thinking of the Zohar. In any case, androgyny is a sign of simultaneous points of view and paradox.
Catholicism as a motif
In this story, Catholicism is a domineering tyrant faith who will never coexist with other points of view. Part of the problem is from Esther's background, because Catholic Spaniards destroyed her community and her religious practice in the Spanish Inquisition. Then, when she arrives to New France, she sees what Catholicism means there. In the New World, religious dogmatism is still an oppressive force, although she feels happy coexisting with Catholicism, if they would allow her to be a part of the community the way she is.