Not gonna try and play counselor like everyone else, but I'd highly recommend looking at your breaker box asap. What you need to know is how many amps each individual plug has. I currently have 2 15 amp power strips which I will plug a 1000 watt ballast and inline fan into each one. That one plug is a 30 amp plug so the 22 amps I'm using will be perfectly safe so as not to stress it out. For a 15 amp breaker, I'd try to go no further than 12 amps on it max. Most homes only have a single 15 amps per breaker, maybe 20 if you're lucky. Not sure what a 600watt ballast amps are, but it should say right on the thing. Next to the 120V there should be a number that looks something like xxxA which will be your amps. My 1000 watt is 9.2 amps so I'm guessing your 600 watt ballast is around 5-6 or so? But if you're using an AC or something else on the same outlet your ballast is plugged into that bumps the amp usage from your ballasts 5-6 to the max, then your breaker trips to prevent any severe problems.
To make it short, see what breakers go to what outlets and then you'll have an idea of just how much you can plug into that one outlet. Make sure to only plug in like 1-2 things that are 1-1.5 amps (like inline fans) with your ballast because you don't want to stress the breaker out so try to aim for using 12 amps instead of 15 or 15-16 instead of 20 kind of thing. So hopefully the room your grow is in has two outlets that are 15 amps each or more, that should be plenty of power. Was she using the hair drier in the same room the grow is instead of the bathroom or is the bathroom power and your rooms power sharing the same circuit?
