It wasn't that Lady Liang wanted to be the villain, inciting her husband to cause a division in the family. After all, as long as the elder was alive, not splitting the family was the right thing to do. By doing so, she would be unfilial.
Lady Liang's thoughts were indeed clarified by the actions of the main branch of the family.
Not to mention the younger ones, but as for the eldest, Madam Lu, with her crude and shrewish tendency to be cunning and take advantage, Xiuxiu wouldn't even speak of her. Given her limited background and understanding, she couldn't be blamed.
What truly chilled her heart was Zhou Xuennian, who claimed to be a scholar. His talent was mediocre, yet he loved to put on airs. He lacked real substance but pretended to be a loftily disdainful intellectual, looking down on everyone. He even had to buy his scholarly title with silver through cheating.