Ali,
I just wanted to wish you a wonderful trip. I've been to Vegas a couple of times,and it is a fun place to go. The Vegas airport was a connection stop for me a few times on various flights and it it is is a very nice airport..All that was before my RSD though, so I can't advise you there..
I did use to be a Travel Agent years ago, please do have your Mom request assistance and make sure the Travel Agent knows that, as well as the Airline. The front of the line is best for sure..: )
Most of all have fun! You deserve that, you are such a sweet person..

Pauliana