The most obvious thing all three of these characters have in common is that they are women with power. Wealthow is a queen, Lady Bertilak is the wife of the master of the castle, and the Wife of Bath is a woman whose life experience and multiple marriages make her...
The most obvious thing all three of these characters have in common is that they are women with power. Wealthow is a queen, Lady Bertilak is the wife of the master of the castle, and the Wife of Bath is a woman whose life experience and multiple marriages make her a fountain of common sense and love advice. Their power comes from their matches with men, but they use this power in different ways. Wealthow uses power to uphold patriarchal structures, Lady Bertilak uses it in collaboration with her husband during their testing of Gawain, and the Wife of Bath uses her accumulated power for her own pleasures and interests.
In Beowulf, women are mostly peripheral. Wealthow is portrayed as a gracious hostess and good woman, but she is a passive character. She symbolizes royal generosity and feminine grace more so than having a defined personality. It is telling that the sole active female character, Grendel's mother, is presented as an unnatural monster and a twisted mirror image of Wealthow.
By contrast, Lady Bertilak and the Wife of Bath are more defined characters. Lady Bertilak resembles Wealthow on the surface: she is a good hostess and noble wife. However, there is a darker side to her, which are illustrated by her attempts to seduce Gawain. She is not an evil temptress, but a tester intent on making sure Gawain is pure. Her actions are done in collaboration with her husband, the Green Knight.
The Wife of Bath is the most three-dimensional of this trio. She is presented as a practical, cheerful, lusty woman who loves sex and life in general. Her attitude towards male authority is far from meek and subservient. Her tale is one rooted in a desire for men to respect women and give them equal authority within the marital relationship. Her relationships with her husbands are diverse: some she married for money and controlled with sex, and others she married for love. The ones she married for love had more control over her. Out of all the women mentioned in this prompt, the Wife's attitudes toward men and male authority is the most complex. Outwardly, she conforms to the status quo but still butts against it. One way she does this is having multiple marriages in spite of this being seen as improper.
How do these characters reflect changing attitudes toward women? It is notable that the earliest example here, Wealthow, is more a symbol than a woman. The latest-written, the Wife of Bath, feels more like an individual than a representation of all "good" women. It could be said that over time, female characters became richer in characterization, though this was not always the norm even in Chaucer's age.