"My plan won't hurt anyone and you won't get hurt either. At the end of the day, we will all be happy and free. You will get your father's property and you will be free to get married whenever you want to." Clara told Mabel.
It was true that that was what she thought about her plan. She really tried hard to come up with the one that wouldn't hurt anyone and everyone would be fine.
Clara was a businesswoman and she had great thinking and a swift reaction to issues. She could have come up with a solution that could hurt people whereas they wouldn't be hurt and they would be happy in the end but she decided to be good and nice, So she came up with the one that wouldn't hurt anyone and everyone would be happy together.
She didn't want anyone to later come back in the future to bother Mabel or call her wicked for making them unhappy and she wanted Mabel to live without guilt for the rest of her life.