i’m confused T_T

I've been thinking the same thing for a few chapters now (￣∇￣")

The Aunt was the second heir because of her brother. She gave up her ability to inherit after she married. So after she conceived a son she killed off her brother so that her son would be the one to inherit the title. The reason why Avery can inherit the title is because she is the only child of her father who was the heir thus making her the heir. In the Aunt´s case she was overlooked because she had a brother but Avery does not have that obstacle.

i’m not too sure but i think it’s like patriarchal society where men comes first.
Avery’s father was heir to dukedom because he was male… and because there is already men in household so the women of that household is not needed anymore but in Avery’s case there is no male in direct line to inherit dukedom she comes first and if Avery had a younger brother… her brother would come first in line to inherit dukedom.

it's because though they place these stories in western style monarchy they don't really understand it. The dukedom would not go to her but go to the next male relative, in this case Matthew. In some cases women had to marry their own cousins in order to inherit their own father's title, which is why Benjamin offered to marry her. But the duke would not be able to "decide" to give the dukedom to her if there are living male relatives according to law.

ahhhh i finally had some idea now thanks to the explanations, thank you for the answers ε=ε=(ノ≧∇≦)ノ

you probably already know the gist of it but if i may, it also refers back to when it said Avery's father died, passing his inheritance(which he got bc he was born a male which makes him heir zz)on to her ,,, so she basically had rights to become the heir that way ;;; jus a add-on on what everyone else said ^^

Exactly