If the vo is satisfied with ur interview and the medical is nt expired at that time,chances are he ll give u visa right away. Review what u wrote in ur application. Both of u discuss these things together. He ll basically relate ur answers with what u wrote in ur application. Some of the questions are basic like what time u start ur job,wages, how many days u work in week,name of ur emplyer,nature of ur job,ur siblings,parents info etc. U and ur wife's answers must match. Also if the vo is satisfied with ur wife's answers he won't call u.
Is ur case straightforward? If there's any issue in ur case then discuss each and every aspect of that with regards to what u wrote in ur application. Bring all the proofs which are not submitted before like new emails,chats,phone records,any bills etc.
Don't worry ur wife be fine. Just ask her to be confident and honest with what she speakes. They respect honesty.
