In addition to tolerance, there are several ways in providing support to diabetics.
Tell them that you are willing to help them in dealing with diabetes.
Learn about diabetes.
Through books or browsing trusted sites that can provide much information about the proficiency level of disease.
Stay with diabetes when they visit a doctor. You can ask the doctor. So, you are equipped to live together in this case to choose foods and inject insulin as needed.
Your lifestyle a little too much will change because of diabetes. Lifestyle changes that of course leads to health.