bluebird1968, I am so sorry that you are in the position of losing your mother. It can be very hard to watch a loved one suffer and it sounds as though she's had more than her fair share in the last few years.
One bit of advice I can offer is to talk to hospice about doing ultrafiltration ONLY. This way the dialysis will not do any kind of cleaning, but you and she will be able to eliminate any fear of suffocating as her fluids will still be removed.
Everything I've heard about death from kidney failure is anecdotal but from what I understand it does not take very long (lots of variables there). I have also heard that it's peaceful and not painful or traumatic. There may be some nausea and sickness in the beginning but as toxins begin to build up she may begin to sleep more and more, with fewer and fewer hours of consciousness each day. One day, she may go to sleep and just never wake up. So, basically dying in your sleep and isn't that the kind of death most people want? Obviously this is not universal and - as I said - I have no direct knowledge, but it seems a pretty likely scenario.
Here are a few links to sites covering the subject:
http://renux.dmed.ed.ac.uk/EdREN/EdRENINFObits/NoRRT.html (Scotland)
And from the NKF, a fairly comprehensive guide called: When Stopping Dialysis Treatment Is Your Choice: A Guide for Patients and Their Families
http://www.kidney.org/atoz/pdf/StopDialysis.pdfI'm so sorry that you and I ever had to meet at all and I wish I could do something to comfort you as you say goodbye to your mother. I'll be sending lots of prayers and good thoughts your way.