@Hakomako
To get its attention and lead it to the Stug.
@Arkhell
"Modern laws of war, such as the 1949 Geneva Conventions, also include prohibitions on attacking doctors, ambulances or hospital ships displaying a Red Cross, a Red Crescent, Magen David Adom, The Red Crystal, or other emblem related to the International Red Cross and Red Crescent Movement. It is also prohibited to fire at a person or vehicle bearing a white flag, since that indicates an intent to surrender or a desire to communicate.[citation needed]
In either case, people protected by the Red Cross/Crescent/Star or white flag are expected to maintain neutrality, and may not engage in warlike acts. In fact, engaging in war activities under a protected symbol is itself a violation of the laws of war known as perfidy. Failure to follow these requirements can result in the loss of protected status and make the individual violating the requirements a lawful target."
also, from another article:
"According to the Geneva Convention, knowingly firing at a medic wearing clear insignia is a war crime.[2]"
From Wikipedia, I don't want bother finding a better source.
And the insignia was pretty damn clear to her, I mean, she aimed for the cross