All that matters is mom. There is no such thing as half Jewish. You are either born of a Jewish mother or convert.
Gal Gadot also comes to mind.
According to Jewish law, that's true.
According to the law of DNA, that's not true.
According to Mormon law, if the Mormons baptize a Jew after death, that person is Mormon.
According to Canon law, if a person converts to Catholicism, that person is Catholic.
We all have our preferred law. I prefer the law of DNA for ethnicity, and Catholic Canon law to determine one's spiritual peoplehood.