Final answer:
The most appropriate staff member to care for the 69-year-old woman with uncontrolled diabetes, polyuria, and low blood pressure is an RN who usually works as a diabetes educator.
Step-by-step explanation:
Based on the client's condition of uncontrolled diabetes, polyuria, and low blood pressure, the most appropriate staff member to care for her would be the RN who usually works as a diabetes educator. A certified diabetes educator is specifically trained to provide education and treatment for patients with diabetes, including managing blood sugar levels, nutrition, exercise, and medication. Their expertise in diabetes care makes them well-equipped to address the client's needs effectively.