I don’t think this is out of character for her. Remember that she witnessed the deaths of every family member and was even framed for them. This is a person who is extremely overprotective of her family and lives for their happiness. She’s not going to simply let people to look down on the ones she truly cares about. Rather, I believe this is her true personality and the polite one was to showcase to her family and herself how mature she is and how capable she is in protecting them.