I agree with you. She didn't have a target at the time, which puts her several steps back from being ready to shoot. Even if she was going to fire a warning shot, her finger shouldn't be there until she's sure the gun is pointed in a direction that won't hit anyone.
I think the problem here is that we're using different definitions of "ready". Let me try this another way: You don't put your finger inside the trigger-guard unless you're comfortable with the gun going off at that exact second and at any given second while you leave the finger there, in whatever direction the gun may be pointed at the time.