@Umbrecola:
I have to fundamentally disagree across the board, even if I do think she factors her brother's well-being too heavily into her decisions:
A) The series' portrayal that his constant worry and anxiety is a result of the childhood neglect he received (not the emotional support he finally got from her later on) seems to check out with reality.
B) If anything, despite her prioritization of him, Lamia's helicopter sister-ing has been
incredibly demanding and occasionally borderline-neglectful of his actual emotional needs (like in choosing to push him to be house head despite him being justifiably terrified of taking the position): Very much a strong stripe of "tiger-mom", except a sister.
C) His "victim" mindset with Aquila is pretty definitely because of what Aquila did, not his sister. He doesn't act like a spoiled child playing sick about this, ever; he acts like someone crushed and traumatized, almost as if with (or come to think of it maybe actually with) PTSD.
From here (and no doubt we disagree) it seems to me more like you're falling into really questionable, reflexive and toxic "emotional support leads to weakness" reasoning.
@Bobman14:
IMO, it shouldn't be hypocrisy in light of her complaint being that her brother was being punished despite having "done no wrong", but the bastard nephew is (supposedly) part of a coup plot. If we find out that the kid himself has nothing to do with the coup and no power in the situation and her attitude doesn't change, then it'll be hypocrisy.
That is to say, it's a false parallel; she didn't condemn the child for being a bastard (in fact I think she thinks he's no relation), she's condemning him for being involved with violence. Possibly naivety and being to ready to rush to anger and judgement on her part, yes—but not inconsistency.