I Will Divorce the Female Leads Siscon Brother

Were getting a divorce
Ethel who reincarnated into her favorite novel has married the female leads brother Liena She thought her marriage life was genuine but soon enough she became tired of a husband who cared only for his sister and whose attention was always centered on Liena yet was cold to her so she filed for divorce
Divorce Absolutely not
However her opponent is a powerful duke so she turns to Terrence the villain of the original story to be her assistant for a smooth divorce
The only person I want to have by my side is you Ethel
But this mans fate is to be hurt by Liena
As the more she knew about Terrence the more he seemed attractive to her