@christinebarnett72 Welcome to Mayo Clinic Connect. If your friend is at 12% kidney function, I hope they are being followed by a nephrologist on a monthly basis? Has there been discussion yet about dialysis, or any dialysis education. There are several options to decide on.

Many time, a person is not aware of how poorly they are feeling when their kidney function starts to fail, if it is due to Chronic Kidney disease. Our bodies are miracle machines, and learn to accommodate our declining function, especially when it is slow. Kidney disease brought on by uncontrolled diabetes or high blood pressure [the two leading causes of CKD] can be helped first by getting those condition under control as much as possible. Having a team effort with diet, exercise, medication if needed, and solid education is all a plus.

Tell us a bit more about your friend's circumstances, so we may be able to give more pointers?
Ginger