She is in surgery at this writing. A federal judge was also reported wounded in the attack as was a child. One staffer is reported dead and reports are fairly specific that a total of 12 persons were injured to some degree.
Guns don't kill people - people kill people has a somewhat hollow cry at this moment. Many of us who have seen the fictionalisation close hand were waiting for such an event, somewhere, sometime and here it is.
Now isn't the time to point at one side or another as there is no evidence available. What is obvious, however, is that a lunatic had possession of a gun and ammunition. I would want to follow that trail first.