Incredibly difficult question.
For me, this is the clearest, most succinct understanding:
FR. A. TANQUERY
Dogmatic Brevior; ART. IV, Section I, II - 1945 (1024-1):
"The Baptism of Desire. Contrition, or perfect charity, with at least an implicit desire for Baptism, supplies in adults the place of the baptism of water as respects the forgiveness of sins.
This is certain.
a) An implicit desire for Baptism, that is, one that is included in a general purpose of keeping all the commandments of God is, as all agree, sufficient in one who is invincibly ignorant of the law of Baptism; likewise, according to the more common opinion, in one who knows the necessity of Baptism.
b) Perfect charity, with a desire for Baptism [implicit or explicit], forgives original sin and actual sins, and therefore infuses sanctifying grace; but it does not imprint the Baptismal character and does not of itself remit the whole temporal punishment due for sin; whence, when the Unity offers, the obligation remains on
one who was sanctified in this manner of receiving the Baptism of water."
It is certain that all who die infused with sanctifying grace are saved (God's grace is not communicated to the reprobates in hell);
It is certain that sanctifying grace can operate outside the visible Church (e.g., valid baptisms in some sects, etc.);
It is certain that men can be joined to the Church by sanctifying grace, even though they are not members of the visible Church;
It is never certain if or whether any particular person has met the requirement of implicit baptism of desire, because making this determination requires knowledge of the internal forum, which is known to God alone.
Therefore, in the case of the Jewess, was she saved?
The presumption is that this Jewess died a Jewess, and therefore was damned.
The possibility is that this Jewess had an at least implicit desire for baptism, but only God can know.