Esther dropped a purely Jewish name, Hadassah, for an apparently Persian name.
Esther means "star,” —a very common name in all civilizations, like Stella.
The only thing she has left is a vague connection with her cousin Mordecai, but aside from that she is as anonymous as the other wives of Ahasuerus, or the members of the United Nations.
She tries to blend in with the others, to assimilate.
Suddenly, she has to cope with a frightening decision that challenges her past, present, and future: "You and your family will perish."
What finally makes her decide is not only that Mordecai is Jewish but that she, the queen, is, too.
This decision is replete with danger because she must identify with Mordecai, and with her people, but also realize that she is directly targeted by the extermination that threatens all Jews.
This is what it is to be Jewish and has been the lot of Jews throughout history, with periods of more heightened resolution, such as Esther's.
–Rabbi Adin Steinsaltz
From The Seven Lights by Rabbi Adin Steinsaltz