Yes, in many contexts žena means manželka. Especially when it is specified as "má žena", "tvá žena" or similar.
First I wrote "krásná", but it got rejected. Is "krásná" used for beautiful and "pěkná" for pretty?
Isnt "Tvoje zena je hezka" acceptable as well? I think Ive learned it that way in my Czech class.
yes. That is accepted as a correct answer as well.
Why "tvoje zenu je hezka" is wrong?
The subject must be in the nominative case.