Not knowing how long she has had kidney failure let me first give you some insight as to a couple of things.
There is Acute and Chronic renal failure - Chronic can be staged 1 - 5. - Stages of renal disease are based on the GFR (glomular filtration rate) of the kidneys. This is an indirectly determined by the creatinine levels. Your Dr. can tell you where your mom is on this list. Loss of renal function over a period of months or years helps determine where you are through the five stages. See the link below to give you a list of the progression.
However - your best help for your mom is to help her with slowing the progression to the end stages by treating her blood pressure and treating the cause of the failure.
Do the best you can. Work with her Dr's advice. Gain as much knowledge you can in the treatments and management of her disease and its progression.
Start at the above link and digest as much as you can. Find help where its available in your area and give mom the best years of your life. You only get one of those.
If this has helped please click "accept" for my answer. Good luck and good health to you and your mom. Take care.