My mom, the stubborn diabetic. Am I right? Or is she?

My mom, god bless, is the most stubborn person I know. She was recently diagnosed with diabetes, and it’s not very well controlled. Her bloodsugar goes up and down constantly.

I keep telling her she has to switch to a low-glycemic diet and lose weight. She says it won’t matter because she has no residual insulin production, and that whatever she eats, she can just take more meds.

When it goes down, she eats and drinks sugary things, soda, chocolate etc.

Am I crazy, or is she the worst and most stubborn diabetic ever?