Not really. While Katerina is your woman sounds ghettoish in English and strongly suggests you are not married, žena when used with a possesive proverb in Czech is married to the subject of the sentence. Žena in those cases can and actually must be translated as "wife". Same goes for man/muž.
Ok. If the man is not married to the woman, but lives with her for years and maybe they even have a child then, Czech: "Ona je tvoje žena (ne manželka).", English: "She is your woman/lady." Of course, the usual "girlfriend-přítelkyně" is probably more used, but is not a rule. So how then?