I think FL still loves and believes in ML. She believes that he is able to save her family (except his father and Zhao), even if she doesn't show it, I think she acts coldly because of Meng who always tries to test her. With Meng, she tries to destroy the bad business of ML's father and Zhao: opium and weapons trafficking. Of course Meng doesn't have the same scruples and doesn't want to spare ML who is the most innocent of all (and his sisters). As for ML's sisters, she has always liked them. She is a reasonable person and has a sense of discernment. She even told ML that no one chooses their family... I agree with shadowdreamer that the drama does not accurately portray the story of the novel. In the drama, we don't see that even her brother is in love with her when it is well specified in the novel. When the parents took her in, she was supposed to become his fiancée...
As for ML's sisters, she has always liked them. She is a reasonable person and has a sense of discernment. She even told ML that no one chooses their family...
I agree with shadowdreamer that the drama does not accurately portray the story of the novel.
In the drama, we don't see that even her brother is in love with her when it is well specified in the novel. When the parents took her in, she was supposed to become his fiancée...