DerZinker

This:
Listen to her. You could be sorry if you buy tickets before you have a visa in-hand... Worst case scenario he will have paid 2x the price for nothing!

Ditto. CDJ is a fine city with its own set of problems, and there are hotels, shopping malls, movies, restaurants--everything you would need right around the consulate, and security is top notch. treat it like a little vacation and you will find it very enjoyable, and you will meet all sorts of people from all over Mexico and their spouses from all over the US all there for the same reason. It's not like a big party, but you will meet many people with a lot in common.

Previous poster is right, but you should be on you guard in Juarez. Just as you would be in any strange, large city. Don't overworry yourself about it, but do be careful, avoid strangers and offers of 'help' from anyone you don't know and don't take any unnecesary risks like going out at night and you'll be just fine.
As far as the taxis, if it works anything like the airports in Mexico then they may just have assigned taxis that are specific to the central bus station. I haven't taken a bus in Mexico in years, but I do remember that when I took one from Guadalajara to Mazatlan, there were taxis that worked out of the bus station and it's unlikely you'd have problems with a cab driver who worked out of the bus station. If you really want to be sure, you could also try to google 'Sitios de Taxi Cd Juarez' and call some of results to find out what the deal is at the bus station, but that is overkill IMO and if you don't speak Spanish you really won't get anywhere doing that. To be on the extra safe side, avoid hailing a random cab and just arrange or have someone else arrange a cab for you from one of the nearby 'Sitios' (or from right there in the bus station like I said). I doubt you will have any issues with this.

Welcome to VJ and good luck to you Good for you for filing and getting the process started.
Honestly I don't know for sure what the results will be, but I believe that usually what happens in these cases is that the beneficiary (your mom in this case) will be denied and then you, the petitioner, will file a waiver for her, which I'm pretty sure is form I-601. It's actually very common that they get these kinds of cases in Juarez all the time, so don't think you're alone Anyway, once she is denied the visa in Juarez she'll need to stay in Mexico for awhile (which I understand is from 6-12 months or so) and then she'll have a waiver appointement in Juarez eventually and then that's the moment of truth. That's my very general and loose understanding of what you can expect anyway.
While you will find a lot of helpful information here on VJ, I would recommend you check out this website: http://www.smf.juarez-mexico.com/
There you can find forums with people discussing almost exactly what you are going through and you will find information specific to Juarez and the I-601 waiver, etc... Another good site to check out where the waiver petition is frequently discussed is: http://immigrate2us.net/forum/content.php
But that first one I gave you will probably be more helpful to you. So I would try those sites and reach out to someone there for help and advice and I'm sure someone will be able to explain it better to you than I can. You may want to consider talking to a Lawyer if you haven't already... But I know I wouldn't do that unless I had no other choice and if you spend a lot of time on the forums at those two sites I mentioned to you, as well as here on VJ, you can probably get away with doing it yourself. Best of luck to you.

First of all, PLEASE DO NOT WRITE IN ALL CAPS It's horribly obnoxious and hard to read. So stop it. Please.
Don't worry though, I forgive you. For I am kind.
If you are asking about support letters from friends and family, and I assume you are, I really don't think that it matters too much when they are written, so long as they are relatively recent. So you should be fine to go ahead and start collecting support letters now.