Surely this is an unnatural sentence in English? I can't imagine ever asking "what kind of wife is X". Just as there have been issues of objectification with "whose is that wife", I'd suggest similarly here?
It is rather to practice on how to ask how anything is, wife is simply a new word that is also being practiced at the same time.
For example through this you now know how to ask what kind of person Katerina is or ask where Frantisek's wife is.
I had a curious thought when I read the phrase "Jaká je Žofie manželka?"... For me it meant "How is Zofies's wife?" ... As if Žofie was married to another woman... Couldn't that also be the meaning of this sentence?