Shock I don't care what happens to me or the people I love. I have a creed and I will follow that creed to my death.
I do not harm the innocent.
I get that and I'm not justifying what she's doing, I'm just saying, of all that she's killed, do we know they're innocent, and at the end of the day, does she care? We're emotional beings, what she did can be seen as berserk behaviour, but I can see
where she's coming from, plus she literally has an evil force in her saying kill kill kill the mobsters.
As LKartillery said, we haven't seen her killing innocent people in game. I can see her killing people close to and associated with the Medicis and it can be tragic especially if some of the people were forcefully indebted by way of servitude and were killed in the crossfire. My point is that, she's a 13 year old kid on a roaring rampage of vengeance. Let's just say she's not possessed by a mystical force. She knows a group was responsible for the pain and horror, upon further research, she finds they're a mob family. She then, if anything, feels more justified in wiping them out.
If you've ever seen Avatar the Last Airbender, compare her to Jet, he was orphaned by the fire nation and went to extreme lengths to seek revenge.
I
don't think she's justified in killing anyone who
might be connected to the Medicis. The whole point is that her logic isn't stupid. It's tragic and twisted, but it's something that shouldn't be so easily dismissed. It's like Frank Castle himself said "Revenge is not a valid motive, it's an emotional response." From us, the cool headed, stable people it's ridiculous and maybe crazy, but when you're hurting so bad, you're not doing checks and balances and using logic.
If we're judging her actions on morality, wholesale slaughter is a big no-no. Judging her actions based on logic (i.e. dismissing her viewpoints as "stupid) don't hold up as well since we're holding her to a different standard and in us vs her, she's not on a level playing field or sound of mind.