I'm an insulin-dependent diabetic and just wanted to say that planning meals for a diabetic isn't as simple as "no sugar." All foods turn to sugar, some just do it faster than others. Some diabetics count the # of carbs they eat every day and eat a well-balanced diet including fruit. I have trouble with fruit raising my blood sugar. I can eat pasta without adjusting my insulin, as long as limit it to a cup & don't have any other carbs. I have a friend who can eat fruit, but has a terrible time with pasta.
The best thing is to avoid casseroles, so that it's easier for her to figure out how much of the food she can eat. You might also want to ask her or her husband what types of things they eat and IF they eat dessert. In our household, we only have dessert on special occasions. It's a lovely idea, but even though we're "used to it" many diabetics do feel a bit left out if they can't/shouldn't eat something.
Deb
BTW - Things like peas, corn, lentils, winter squash, yams & beans (limas, kidney, great northern, split peas, blackeye peas) all count as carbs.