[Shoshana]

I'll try to answer some of your questions but I hope someone else will chime in and give more detailed (accurate?) answers.

I believe the only people who are considered Jewish by the Orthodox and Conservative movements are those born to a Jewish mother. Reform Jews (some? all?) accept patrilineal descent. ( Of course, Hitler believed anyone with even a small portion of Jewish blood from past generations to be Jewish.)

This is why adopted children need to be converted to be considered Jewish. (Unless of course the birth mother, or father in the case of Reform, is Jewish). As both an adoptee and a future-adoptive mother, this aspect of the religion is not one I am fond of.

One can be 'culturally' or 'secularly' or 'ethnically' Jewish without practicing the religion. These are people born into a Jewish family/community who either did not practice the faith as children with their families, or who choose not to practice as adults. (It is my opinion as a single convert to Judaism) that is difficult to 'learn' this cultural identity as an adult ;-). I do not believe that Jewish is considered a racial category among any of the movements in Judaism.

Children are accepted as adults into the the Jewish faith at the Bar/Bat Mitzvah. They 'reaffirm' their commitment to Judaism at the Confirmation (which occurs prox age 16 if the child continues with religious education post-Bat Mitzvah).

Many children are being raised in inter-faith families. While the religion itself may not have a 'half-Jewish' construct, these children do indeed have ties to both a Jewish and a non-Jewish heritage.

I learned that I had a biological great-great grandmother who converted from Judaism to Catholicism when she married and left Poland. Since the matrilineal decent ended with her conversion, she was the last Jew in my birth family.

The people at the synagogues I attended before I made the decision to convert were amazing and incredibly welcoming.

In your case, you weren't raised Jewish and as an adult have not converted to Judaism, so you would not BE Jewish. However, you STILL have a Jewish heritage that is yours to claim and celebrate.

Hope this helps a little...