But in her defense it's really quite a gamble since it's just a hypothesis at this point with no actual long observation of what that shackles can do and they do no more about their family's condition since they're the one who usually experiments on their blood BUT yes her pride might be the one stopping her from listening to the FL since she's got "replaced" by her at some point.
Its a gamble with nothing to lose, he was going to die regardless in her eyes she just didn't want the MC to interfere with the family despite the fact that she married into the family already.
dude this family is just tragic bro iwant to hug each and every one of them except for that one particular bitch that thinks she knows everything bcs shes a doctor like get your fucking head out your ass and put down your pride