kate Hudson's mother, goldie hawn, is Jewish. judaism, as an ethnicity, is passed down through the mother, so yes, kate is Jewish, unless she has become an apostate by taking on another faith (note: not practicing, or even failing to believe, would not deprive her of her Jewish heritage or render her an apostate).
says kate:
"I'm part-Jewish, Hasidic Jews - they don't cut their kids hair until they're three. "I'm not very religious, but it's actually kind of beautiful, they compare the men to a tree and trees don't bear fruit for three years. "So I just figured maybe on his third birthday I'll cut it. I'm going to cry my eyes out!"
(there is btw no such thing as "part Jewish" but that is obviously how she considers herself.)
wikipedia says:
Hudson is of Hungarian, Italian, and Ashkenazi Jewish descent,[6] and was raised in her maternal grandmother's Jewish religion;[7][8] her family also practiced Buddhism.
Buddhism isn't a faith, so that would not make her apostate
Read more: http://wiki.answers.com/Q/Is_Kate_Hudson_Jewish#ixzz1wBPU7xhX