Well, I won't lie, she is at risk. Diabetes is nothing to mess with, and I am sure hep c isn't either. A couple suggestions, you can try asking her to take a walk with you, see if she will drink sugar free soda (check on that, I don't know if that is ok for diabetics), and see if you can come up with some delicious healthy food to make her. Grilling food is way healthier as a rule than frying, or you can bake, but I am almost sure grilling is the best (eh, double check on that too).