Insane that the original story she was he villain like ?? A victim taking revenge isn't ...

If it is her abusers or people qho font know the story she might look like the bad guy.

But even from the point of view of the reader you see someone extremely abused who take revenge only on their family and you think "oh poor family they didn't deserve that ??"

As far as I get the story was a novel or mc read the novel and if the novel has an biast and unreliable narrator then you can show her as the bad guy by not telling her story. If you only show her taking tevange or acting out and not why she does so then she could.easily be shown as a spoiled brat or villain who is ungrateful and mean spirited.
Her family knew what they did to her but still saw what she did as her being the bad guy. They knew she was being ahused but because they believe they are in the right then she becomes the bad guy for not being grateful for what she gets, somethjng that in their eyes might be more then she deserves.

I think it is kinds interesting how those stories are build on having a narrative and a story teller who is on one side and since we don't get the other side or when we do then it is still told from those who did the abuse so it is being justified. Think about how many stories real or fictional where this could apply.

I do love a villain who is just evil because they are evil, but most people are victims before they become the villain