@BalrogDeMorgoth it probably refers to a bar of "animosity against the Host", similar to the favorability she got from the ML. So rather than the FL being 'more evil' than in the original plot, it's just that she completely hates Su Luxia.
Though it could also be that in the original plot her actions weren't as "evil" as we think: She bullied Luxia enough for her to kill herself, but that wasn't her goal, she simply didn't really care about Luxia nor saw her as a threat, otherwise she could've done worse.
The real daughter was slightly more dangerous, so she got a way harsher treatment, but things are different now and they're both SERIOUS threats to her lifestyle meaning the FL will hate them a lot more than in the original novel and can go for a far more cruel revenge