You can read about Xeloda by going to pdr.net, clicking on 'physicians', then 'pdr on line' in the left hand column and then typing in 'Xeloda' and checking on 'PDR full text'. I just did this. Xeloda converts to 5-Flourouracil in the body. This is a strong antimetabolite.
Chemotherapy can kill or it can give the patient some extra time.
I hope your mother's physician warned you that your mother was near the end either way, as she had a recurrence. It is possible that your mother told the doctor that she didn't want him to tell you how bad the situation was and that he honored her request, therefore, what happened was a surprise to you. I think the best thing to do would be to go to her doctor, the one who gave her the Xeloda and ask him why he suggested that and whether he had told your mother what the prognosis was and how she reacted. Knowing how to balance on the tightrope of dealing with dying patients on one hand and their families on the other hand is one of the most difficult dilemmas physicians have to deal with. I think he can tell you more than anyone else can.