Alright, as a declarative question expressing surprise it is actually possible. But that usage I would rather translate as "Ty znáš jeho druhou ženu?" "Vy znáte naše děvče?"
Like this, from a Czech thesis about Declarative questions in English and Czech https://theses.cz/id/8mx4qg/Kube_BP.pdf :
„But it was all right, I didn't mind. But then, when the official part was over, I was nobbled by a man in the English Department. Name of Dempsey."
"Robin Dempsey," said Persse.
"Oh, you know him? Not a friend of yours, I hope?"
„Ale prosím, to by mi nevadilo. Jenomže po tý komedii se na mě nalepil jeden chlápek z katedry anglickýho jazyka, nějakej Dempsey.“
„Robin Dempsey,“ řekl Persse.
„Ty ho znáš? Doufám, že nejste kamarádi.“
„V žádném případě.“
I am not super-convinced about the correctness of the "You know his second wife?" either, but perhaps... Or do you really claim that "You know our girl?" and "Do you know our girl?" are the same kind of question?