Questions about immigrant visa interview in Ciudad Juarez

Hello all,

Thank you for your time in looking at my question.

I have been in the process of sponsoring my wife for her green card. Our I-130was approved and I have sent in the I-864. I just sent in the DS-230 orapplication for permanent residency this week. I haven't received an appointment yet but I'm hoping the NVC won't take too long to review our case.

We are in Mexico now and have been here since before we started the process. I'm a US citizen and I spent 30 years in the US. However, my wife and I as a couple have never lived in the US. Now we want to go there and live for a while for our son's sake (schools and contact with my family). My son is a US citizen by consular birth abroad and has a US passport. My wife has never entered the US illegally and has never had a problem with immigration. We are not applying for the K-3 but rather directly for permanent residence status. Because she is
not in the US now, we will not be applying for a change of status.

Ok, now my questions. When we have the appointment...
1. Do we know about approval or denial right away?
2. If approved, is she required to enter the US immediately? or will she be
given a time frame in which to enter the US? I really need to know the answer to this question because that will obviously require changes in our planning.
3. Is there any advice anyone can give us about the interview? specifically in Ciudad Juarez?

Thanks a million for you help, patience, and time!
sincerely,
Daron