Maybeas an officer you’re trained to give aid/cpr to someone you’ve shot.
As a private citizen I would not do so out of grave concern they were playing possum.
Yes, her training would be to preserve life, if possible, even in these circumstances.
I don’t think anybody would have blamed her if she hadn’t tried to do CPR in the circumstances - she could have legitimately argued she was in shock herself or that she feared he was faking.
But it looks like she did the job she’s trained to do in literally text book fashion.