Sadie Adler

Is Suige the only one who thinks Sadie is weird? I want at one point in a mission Arthur goes shopping with Sadie and Sadie wants to kill the salesman. The O Driscolls killed her husband, she sees them as monsters for what they did and she was ready to kill a guy who had done absolutely nothing to her for fun who maybe had a family. She would have done exactly like the O Driscolls. It's really strange.