So Opal came up with a plan. She drew up documents with her uncle's help (basically borderline fraud). Hubert signed off on the documents thinking nothing of it. Opal then announces that she now owns everything under the McLeod title...the land, the funds, and debt. She tells Hubert that he is going to have to work to buy back everything back from her, piece by piece. She promises that once he buys back everything, she'll give him a divorce and he can keep everything he earned back. She uses this opportunity to have him learn how to actually manage a territory by working with her father and uncle. The first thing he works to buy back is his primary mansion.
During this time, they live separately (because Stella and her mother are still in the mansion). Opal is living at the other house in the territory where Omar is (the guy who embezzled) and she actually helps rehabilitate him with the help of some of the staff and trains him on how to become a proper manager to the territory. This whole time, she's working on managing everything with the dukedom, slowly giving back the rights to Hubert as he earns it.
Hubert moves Stella and her mother (plus the butler and maid who are jerks to Opal) to a house in the countryside of his territory that he earns back. Opal discovered that the doctor that was seeing Stella regularly was incompetent and over-billing Hubert for his services. They found a legitimate doctor who recommended Stella to move out somewhere with clean air, away from the city, meaning away from the main mansion (HA!). It's suggested that Stella and the last doctor were in on the plan together to keep her in the mansion, but Hubert doesn't notice and is grateful to Opal for finding a real doctor for Stella.
There is a time skip of seven years. After some drama with some property that Hubert stupidly invests in (which Opal helps him with), he finally has enough to buy back everything from Opal. He's super happy and he gets down on one knee and proposes to her, to have a real marriage. She tells him straight up, "No, give me the divorce like we promised." and goes on to tell him everything she endured just so she can have her freedom back. (SO SATISFYING) He begs her to stay (even stating that Stella is nothing more than a sister), but in the end, he gives her the signed divorce documents.
Before she leaves his territory, she visits Stella and her mom (and the b**chy butler and maid) and she tells them she has great news and the staff all freak out because they think Opal is there to fire them. Instead she tells them she's now free, she's no longer married to Hubert, and with a big smile on her face, she says, "Hubert's definitely going to get remarried, so please give the new wife the respect and kindness she deserves, because she's probably going to be much younger and less tolerant of impoliteness." and leaves without turning back.
She returns to her home and Claude finds her there. They confess their love for the other and he tells her that he's actually the Marquis of the neighboring Taisei Kingdom. During the seven years she was married to Hubert, he resolved himself to take back his title from the Kingsdom (for her sake) and also he's been quietly helping her with a few problems she had (like the investment fiasco Hubert got into).
I didn't continue reading after that but it looks like it's a new arc with Claude in his Kingdom.