That damn aunt, just die!!!

Yep. There are two things that readers blaming the mc are not completely getting about her situation.

1) Is that she's realized the past is no longer the way she remembers it, both because the past is changing a bit and because there are many things she's realizing that she failed to understand the first time she lived it... Like, for example, the fact that her aunt had replaced all the servants and thus had full control of everything that happened inside the house from behind the scenes, or the fact that her brother hadn't wanted her to take his dead sister's things just because he was being "mean" to her, but actually because he was also trying to protect her from the dangerous "gifts" their mentally unstable mother would sometimes give to her when mistaking her for her dead daughter ("gifts" that were actually dangerous to a healthy child like her, unlike with the sickly "previous" daughter).

So, her knowing the past is no longer going exactly the way she remembers it means she'd obviously feel more cautious and uncertain about the outcome, and therefore more insecure about the "correct" way to deal with events.

And,

2) She can't just get her brothers and other people what is going on (the aunt bullying her, the brother sleepwalking, etc) because they might not take it well coming from her who is still "an outsider", or that they might say she is just exaggerating, sounding the alarm and one-sidedly creating drama out of things that "are not that serious"...
People need to remember that, as much as her relationship with her bros has improved quite a bit, she still has a long way to go in order to get their full trust in her words.

* She can't tell her brothers and other people about what's going on.

Sorry for that messy sentence.

All good, I understand your point tho^^/
And yeah, as you clearly state it obviously, there are still some people can't see it, it's so stupid of them tho!!!