I don't want to argue semantics, but the title of her thread is how to lose my flabby arms. You can't lose any flab without dietary changes. I can build all the muscle I want, but all I could hope for is that it will pop through the fat. The arms would still look soft though and not 'toned' or harder, without losing water + fat in the area, essentially a leaner, less flabby arm is what she wants. Correct me if I'm wrong.
With that being said, arm exercises and diet, with diet being more key. Checkout Fitday.com or similar for an easy way to track calories and your diet. This website has dietary tools as well.
In addition, a lot of time simply manipulating carb intake, (time of the day, as well as amount taken in) will dramatically reduce water retention and quickly reduce the softer look.