And it might come from secret, from the word seter, lehastir, to hide. But the story goes that the Biblical
Ester wanted to hide the fact that she was Jewish so she took a Persian name instead of her original Hebrew name,
Hadassah. From that, we can know that it was a Persian name, and she used it because it was a Persian name, probably with no relation to the Hebrew word for secret.
And there are women in
Israel named
Ester. Don't know if it's many.