Maybe it wouldn't be a good idea for her to eat too many cherries or bananas because she's a diabetic, but if you're not a diabetic, I don't know why she would try to tell you they aren't good for you. No more than 5 cherries per week just seems a little ridiculous if you ask me.
If you feel okay after eating some bananas and cherries during the day, then that seems like a great meal.
Worrying about what you eat can weaken your digestion. Keep your mind out of your stomach :).