We had a long sermon a year or so ago about how "without Esther, there is no Easter". That she played a critical role in salvation history and was thus a participant in your salvation.
Indeed. From such viewpoint, all of JESUS human ancestors, ... plus a host of other folk who manipulated circumstances here and there, ... played a part in and, thus, ... was a participant in our salvation, as well.
Yes! Exactly so.
And by comparison to Christ Himself? None of them (including Mary) contributed anything of consequence. Without Esther? God would certainly have picked someone else for that role - and that would be the person who participated in our redemption. None of them is even noteworthy by comparison to Christ.
It is in comparison to other humans that Abraham, or David, or Daniel, or Esther, or Mary... have any real standing. And Mary certainly had a more significant (or perhaps "immediate" is the right word) role in bringin Jesus into the world than Esther had.