Arianna was not okay, she was frozen in shock, having watched everything play out right in front of her. She had not only narrowly escaped being killed by bullets but watched Samson devour a woman right in front of her. It was a very traumatic sight and she was covered in sweat.
Her stomach couldn't help but churn at the bloody scene. As much as the woman had come to take her life, she still didn't deserve this painful end. She was probably a mother or sister to someone and she was gone just like that.
However, Arianna's heart hardened in the end, the woman had come to take her life and it was no fault of hers she met a terrible end. Samson had only been doing his job. Arianna wondered if the woman thought about how her action would cause her loved one's pain before attempting to take away her life. Never take away a life that you can't give. So no, she refused to feel any more guilt.