Her dad is Jewish, mom isn't, and parents are divorced. The extent of her religion is "we said the prayers on hannukkah." Last night she heard about some right wingers she's barely related to say that Jewish people go to hell. This then led to my gf saying that "the left" also does the same thing.
Is this what the kids are calling "the ick"?
I was in a remarkably similar situation during one of Israel's offensives in the 2010s. The sense of ethnic identity, in the absence of a commitment to internationalism, can be overwhelming. You might be able to salvage this but she needs to have enough conversations with anti-Zionist Jews.
It can't just come from you. She must talk to a Jew. Better not one but a few. Simply none else will do.