How do the women in The Adventures of Huckleberry Finn play similar roles?

The main women in Huck's life all fulfill the same basic role, trying to "civilize" Huck - all without success. Starting with the Widow Douglas and Miss Watson and continuing right on through to Aunt Sally and Aunt Polly, they all attempted to act as the mother-figure that Huck didn't have and to bring him to a different way of life.

The Widow Douglas, she took me for her son, and allowed she would sivilize me
Aunt Sally she's going to adopt me and sivilize me and I can't stand it. I been there before.

Sophia Grangerford and the three Wilks sisters (Mary Jane, Susan and Joanna) are lesser characters in the story, but do fulfill a different role for women. All were young and under the care of family members, but all were also independent enough to make decisions and take action without consulting their elders. Huck admired their ability to shape their lives themselves - as he did with his own way of life.

What stereotypical roles do women take on in The Adventures of Huckleberry Finn?

The book was written in a time when women were not considered equal citizens to men, so during the story the women are seen in roles that were considered "correct" for the time. Women cook, clean, and act as teachers and moral guardians in society. Interestingly, Twain depicts women as being generally more moral than men, since they care more about their families, while the men are generally more concerned with material wealth and comfort.

Her sister, Miss Watson, a tolerable slim old maid, with goggles on, had just come to live with her, and took a set at me now with a spelling-book.
(Twain, The Adventures of Huckleberry Finn, gutenberg.org)

Huck has no real need to either empathize or pander to women, since he believes that adults of both genders are restrictive. He observes that women are often the influence behind the more powerful men, but that they stay in the background. However, it is also interesting to note that the major influences on Huck's life -- leaving aside his father -- are female, and that the immediate families of his friends (such as Tom Sawyer) are often composed of "Aunts" instead of "Mothers."