
I understand why hate the sister has so much hate. She is annoying.
Points:
1. She knew her brother transmigrated and yet she felt disappointed.
2. When the CP saw the two of them she was willing to blame his brother as being forced (As a woman who came from the modern world she would know the implications of the words she is saying) Like that's your brother (She can actually make up a different type of excuse.
3. She wanted her brother to follow the plot. She is okay with the situation where his brother would sacrifice someone who he grew up and literally friends with, without knowing the person (Her lady is friends with Grace. He saw his brother hesitate and she didn't even gave him sympathy). She is literally selfish.
She is really a bad written character.