This guest contestant here is the legendary Italian actress Anna Magnani. As I said, I doubt most people here have seen her (though some surely have -- I will vouch for Nell Minow, without even checking first), and many people probably don't even know of her. But two years after this appearance, she would win an Academy Award as Best Actress for the film, The Rose Tattoo. She starred opposite Burt Lancaster, and Tennessee Williams wrote the part expressly for her.
The segment comes at the 17:45 mark. Though she speaks English well-enough to have done so in The Rose Tattoo, she clearly feels more comfortable in her native language and uses an interpreter here. (Since this is two years before The Rose Tattoo, perhaps she was still working on getting better at it at this point...)
Anna Magnani (17:45) Interpreter, soon to win be Oscar for Rose Tattoo, three years
And what the heck, let's just toss in a bonus video while we're at it, just because you've been so good lately. Here's an almost 8-minute clip from her Oscar-winning role, so you can have a better idea about Anna Magnani .and her talent.