I can only assume that those blood stripes, caused by droplets landing on her arm, were from the first wound when she was in a semi-sitting position and because of it being from a vein and not an artery, and because of the time between shots when she held the rifle in readiness for the second shot it would have travelled in this way if her arm was across her body adjusting the rifle in place.
I can picture it in my mind but it's hard to try and describe when it comes to writing it down.