Probably bc the brothers and dad are crazy psychos? You can't tell crazy psychos off, especially extremely capable crazy psychos. They don't care if it's women or men, they just kill bc they can and no one can clearly stop them. She also has most of her mana locked (as she explained so many times already) and is in a body of a weak BABY. At least she's smart enough to pretend to be one. I doubt her fam would be happy when they learn that she's actually the archmage bc it can be portrayed in a way that what she did was body stealing. Especially since her fam isn't really fond of mages.
No like I said they cant really kill her bc shes literally the symbol of the empires strength, she’s already won them over (and she knows it) and she’s the most popular person in the empire too. It’s not like she’s in a position where she’s actually below them like the one from Emperors Daughter. Ig its bc she hella old and don’t care lol. I’m just tired of these plot holes where “royal nobles” having no manners or consideration like they were born savages or somethin
The brothers and dad are kinda dumb assholes and it’s not like other webtoons where society is misogynistic and the baby has to suck up to them to live (since she’s the important third sun) plus she’s smarter and stronger than them ://