Of course, we now teach that the soul comes from God at some unknown point, although the materialist soul seems to begin at gastrulation rather automatically. The immortal soul cannot be measured, even now, nor will it ever be. As for modern Judaism, if your mother was not Jewish, she must convert or you won't be. Children of Jewish fathers and gentile mothers who did not convert are not considered Jewish among the Orthodox. Reform is different and I don't know the Israelite/Romany rules, which govern whether I am in a tribe or not. My mother was Gadje (gentile). That I am genetically Roma (gypsy) is no doubt.