"My sisters are married."
Translation:Mé sestry jsou vdané.
So I used Moje sestry jsou ženatý. Is this wrong because it should be ženaté?
"ženaté" would be the correct declension but women cannot be ženatý/é, only men can. Women are "vdané". And I think it would be the case even if they happened to be married to another woman or to each other.