My 96yr old aunt is stage 4 renal failure. Congestive heart failure, hypertension, no dialysis. How long does she have?

Life expectancy. You ask a difficult question. Stage 4 chronic kidney disease (ckd) is far advanced stage of ckd. The life expectancy (l) of a 96 year old female in the us is 3.18 years. That is the l without ckd. Patients with ckd live shorter than those without it. Your question is a difficult one to answer and i hope this helps.