Translation:Grandmother said that normal boys do not eat so much candy.
At least not in US English, since candy is a singular (although collective) noun. I reported it with an explanation.
It would either be "so much candy" or "so many candies" but it has been fixed.
Often there aren't any translations anymore. Why is that? This specific sentence is easy to understand but generally it was very helpful to almost always get a translation.
To go: я Еду, мы Едем, ты Едешь, вы Едите, они Едут.
To eat: я ем, мы едИм, ты ешь, вы едИте, они едЯт.
The perfective aspect shows that one listened to her and stopped eating candies? (=as a result of the action of speaking)
I'm not exactly an expert when it comes to the difference between perfective and imperfective verbs. That being said, I don't think that you can draw this conclusion. Perfective just shows, that the action (the talking) was completed successfully, rather than being ongoing, incomplete, habitual..