Good grief! Miss Watson just will not give Huck a break. As one of Huck’s guardians before Pap steals him away, Miss Watson is definitely Huck’s least favorite pseudo-mom. We imagine her constantly shaking her finger at him and pulling him around by his ear. Miss Watson never married, and at the start of the novel, she’s just come to live with her sister, the Widow Douglass. Huck describes her as "tolerable slim, with goggles on" (1.6). She has very little patience when Huck doesn’t understand certain things, like stories from the Bible or how prayer is supposed to work. When she tries to sell Jim down the river and away from his family, her reputation in Huck’s mind just goes from bad to worse.
In the end, Miss Watson does (sort of) redeem herself – she feels guilty about trying to sell Jim, so she sets him free in her will. She could have been bitter about him running away, but instead she actually shows some compassion. So despite her nagging ways, she does seem to have a good heart.