Food waste, any advice?

Pasa makes a good point. Why doesn't she like the food? Not enough salt, pepper? Maybe you can be creative.

I am primary caretaker for mom and was annoyed with the number of meal deliveries until I found ways to be creative with them. These are low sodium and balanced meals which aren't too bad. To avoid waste I reduced the number of meals delivered. I added the vegetables to soups or casseroles. The left over fruit skins are added to the compost along with paper packaging. The plastic containers I've used to grow plants and will donate to a teacher for class projects. Mom surprisingly still has a healthy appetite but needs to eat smaller meal more often, so these are good to have around since they are already prepared. On a plate, it looks more appetizing than in its container. Food is food.

If these meals are like Meals on Wheels, they have a limited amount of people they can serve. She may be taking a meal that someone else could use.
Like said let it go.

Stay out of it, meddling will only cause you grief and isn't likely to solve anything.