The 'official' thinking is that there is no need for diabetics to have special diets, recipes or special foods. They should be able to eat exactly the same as everyone else. However . . . . practically every diabetic will tell you that this is only true to an extent. We all have trouble trying to reduce our blood sugar levels, and it is the carbohydrate content of food that increases the blood sugar level. So, if you want to do your diabetic family members a favour, then give them meals that contain less carbohydrate.
In terms of recipes that are good for diabetics I have found Antony Worrall Thompson's "GL Diet Made Simple" book has some really tasty and low carb meals. If you want to go ultra low carb then recipes from the Atkins, South Beach or Dr Bernsteins books are also good.