She’s going to learn in life that this is not the case with all guys she knows she can do it to you because. You have never hit her one good solid time so that she won’t continue being physically aggressive. A lot of boys/men are very different now they have no problem defending themselves or worse. Your aunt sucks big time for not kicking her out for the knife incident next this happens - it won’t be the last since it is condoned - call the police.