Sorry to hear about your mother. As per your said symptoms she is landing in chronic renal disease (CKD). It's better you consult a nearby renal specialist as she might need more support like higher investigations and long term treatment. A basic sonography, her kidney profile blood test along with haemogram and observation of urine output is needed at hand. Doctor may suggest a dialysis depending upon situation. Kindly make an appointment at earliest. Thanks n Regards.