Stories are drawn up with the clear design to warn about the dishonesty of women. From the outright and vicious Albina myth where Albina and twenty-something of her sisters conspired to murder their husbands, to the banishment passed down by women onto poor Custance.
Albina and her sisters are painted as power hungry, improperly craving independence. After they all set their plot in motion, it is only one who displays honesty and confesses her sisters' plans to her noble husband. One in twenty-five. And if four-out-of-five dentists can convince you what toothpaste to buy, can 24-out-of-25 women convince readers not to trust a gender? There's something to be said here for strength in numbers.
In the Man of Law's Tale, even women are encouraged not to trust other women. It is the Sultan's mother who upon hearing about her son's choice of bride, plots to have her put out to sea without a paddle. Only paragraphs later the king's mother does the exact same thing.
Women in these stories are not only depicted as underhanded, operating behind the backs of their noble husbands and sons, but they are done so in a way that prevents the interpretation of merely a wicked individual. By grouping Albina and her sisters and creating a parallel between the Sultan and King's mothers, it is by the default of being women that these characters are branded deceitful.