Hi OP, read my post because I likely know what I'm talking about.
Energy drinks, while not always the healthiest, aren't necessarily life-threatening unless taken in extreme quantities. Even then you would just have an extremely high heart rate and blood pressure through the roof which is only bad if done repeatedly a lot over time or if you have circulatory problems.
If you have to wake up and go to the airport for a flight at 4 AM, that's when something like an energy drink would be useful so you don't fall asleep at TSA. However you don't need it on a daily basis and drinking one once in a while is not going to kill you.
They've been given a bad rep mainly because kids just abuse the stuff out of them and also because of 4loko or whatever it was called, which was pretty much a heavy alcoholic drink mixed with energy drink. If 4loko was drunk in large quantities the alcohol would have supposed to knock you out as per getting drunk normally does, however the energy drink part of the 4loko keeps you awake and therefore more susceptible to stupid drunken behaviors and/or alcohol poisoning.
If your mom is this upset about it tell her to consult a doctor.
no one needs a whole can of energy drink in a single day. its just ridiculous. if you even need caffeine to get by on energy in your day, you already arent living healthy.
Also this. The only times I drink coffee are when I need to wake up and haven't gotten much sleep. I drink it maybe once or twice a month.