Then the answer is simple. Donate Blood.
With gunshot wounds, patients often need blood transfusions. And there is always a need for blood donors. Now, while any blood you give today would be unlikely to go to her, it can replace the blood that she (and the other victims of this tragedy) needed to survive. The supply of blood in the US is often only about 3 days, and at more rural areas can be even less. Donation takes only an hour and fifteen minutes or so (only about 15 min actually donating, the rest is screening questions and resting afterwords). I will often bring my mp3 player and spend a lot of the time just listening to stuff.
Donating blood is a simple way to save up to 3 lives. Rep Giffords and victims of trauma like hers depend on the people that decided to donate a week ago. Will you be one of those people who donate?
The most common reasons people give for not donating is that they haven't thought about it or that they are afraid of needles. I've given many times, and the pain from the needles is minimal, less then if you pinched yourself on the hand. You don't have to look at the needle while they are setting things up. And afterwords you get free juice and cookies!
Find a blood drive near you