Please understand that I can only answer cautiously, given my limited understanding of Judaism. On assertions made about Judaism, I defer to the greater knowledge of those who understand Judaism better than I.
Having said that, as I understand it, rabbis are not the Jewish equivalent of Catholic priests. A rabbi mainly is a teacher, although some rabbis are also judges of Jewish law. Although Judaism uses the term ordination for the ceremony in which such responsibilities are conferred upon a person, it is not a sacramental ordination in the manner that the Church understands ordination. It should be understood that sometimes Jews and Christians use the same terminology, but the words rarely are defined in the same way. Another example is that of confirmation. The Reform movement’s practice of confirming Hebrew school graduates is not the same thing as Catholic sacramental confirmation.
The distinction you make between women priests and women rabbis is an important one. The Church is concerned about non-Catholic Christian women priests because such claims that women can be Christian priests undermine the Church’s understanding of the Christian priesthood. The Church understands the Christian priest to be an alter Christus (“another Christ”) who acts in persona Christi (“in the person of Christ”). Because Jesus Christ was a man, those persons who act in persona Christi and are an alter Christus must be men as Christ is a man. There is also the fact that the Church is bound to Christ’s own example of choosing only men for this role.
None of this applies to women rabbis. If I were to offer an analagous position to a Jewish rabbi in the Catholic Church, I would suggest that rabbis are somewhat equivalent to catechists and canon lawyers. Since both of these positions can be performed by a layperson (man or woman) in the Catholic Church, I doubt the Church have the same concern about women rabbis as it does about women priests. Of course, for the sake of argument, if we consider the revival of the Jewish priesthood, then the Church might be concerned about Jewish women priests since the Jewish priesthood prefigured the Christian priesthood.
