chronic kidney failure

My mother is 82 y/o female with diagnosis of chronic kidney failure followed by her internist for about 5-6 years. Her 12/2008 bloodwork showed a BUN of 29 mg/dl, creatinine 1.4 mg/dl, eGFR 29 mg/dl. Urinalysis was clean with no cast or cells, blood , or protein. She has controlled hypertension (120/60) with atacand, catapress and maxide. She has GERD and takes aciphex, but often needs mylanta and gaviscon for acute reflux. She is on synthyroid, also. Kidney function has been stable for last few years. When would it be advantageous and prudent to see a nephrologist and get some advice on how tis will progress and what she can do to preserve her kidney function. Mayo Clinic has a kidney failure clinic that I would like to take her to. What stage is her kidney failure in and what do you think she should do?