Agree with Lee on walking. Even if it's very slooow walks around the hospital ward, it really does speed up the healing process. It looks like you're going to an excellent surgeon (Dr. Sang Lee at KeckUSC) so you've got that covered!
Also, I wouldn't worry about your mom only getting Xeloda. It's what does the heavy lifting in Xelox anyway. If the surgeon says she will need a temporary ileostomy, make sure they mark the spot on her tummy ahead of the surgery date. That way the stoma and bag won't interfere with her clothing. Also, make sure to ask for an ostomy nurse to train your mom and you on how to take care of the skin around the opening to the bag, as well as the basic mechanics of how to change the bag, etc. The bag seems really weird at first, but you get used to it. I hiked, mountain climbed, and ran several miles a day, all with a bag. Wearing tights or a maternity belly band (available at places like Target) can help disguise it under more form-fitting clothes. The good part is any Xeloda-induced diarhea goes into the bag, so you don't have to make all those potty stops in public places!
My experience: good surgery with no complications, clear margins, temporary ileostomy with reversal about 5 months later. Make sure your mom uses the two month post-radiation break to gain strength for the surgery. Have her eat healthy foods, stay hydrated, and go for walks or whatever she can do to build up some stamina.
Hugs to you and your mom!!!
Julie