I have had 2 kids in my care who would get different food from the others. One got no dairy and the other one was sent his food from home for similar food issues but it was more extreme. Never did it cause a problem. If another child asked why xxx had such and such while they had so and so, I would just explain that xx couldn't have what we were eating and so he/she had different food. I think it was a good thing because it taught them all that we don't always get what our friend has and that is okay.

If mom doesn't want him to have banana and cheese than I wouldn't give it to him but I would continue to give it to the others.