St. Clare’s cousin Miss Ophelia is a pious, hard-working, abolitionist from the North. She's also unmarried, and beyond marrying age. When St. Clare brings her back to his Louisiana home to care for Eva while Marie St. Clare is "ill," we can tell she’ll have things whipped into shape with a disgusted sniff in no time.
Even though she’s an abolitionist, however, Miss Ophelia is prejudiced against blacks. Although readers respect Ophelia’s work ethic and devotion to principle, Stowe also uses her to satirize the subtle racism of the North. Many northerners are happy to tell the South what to do about slavery and to condemn southern practices, but those same northerners are often unwilling to interact personally with blacks.
Too many abolitionists, in Stowe’s opinion, want the slaves to be freed but sent away to Liberia or otherwise kept at a distance. They’re OK with black people as long as they don’t have to meet any. In other words, they’re racist too. (Which makes it ironic that Stowe sends George Harris to Liberia at the end of the novel.)
In a strange experiment, St. Clare teaches Ophelia about slavery by giving her a slave of her own: Topsy. St. Clare lets Ophelia educate and treat Topsy according to her own philosophy without any interference. Miss Ophelia quickly discovers two things: 1) her own secret racism, and 2) the difficulties involved in teaching slaves who have been brutalized and subjugated their entire lives. She tries to do her best with Topsy, teaching her household skills and the catechism, but actually she’s disgusted by the little girl and hates touching her. All her strict discipline and even whipping fails to tame Topsy’s wild and crazy ways. Only when Eva gives Topsy unconditional love does the child begin to change.
Fortunately, Miss Ophelia is an honest woman. When she recognizes her faults, she rolls up her sleeves and dives in to scrub them away. She immediately understands that Eva’s innocent love has succeeded where all her stern discipline failed. She goes to St. Clare and insists that he immediately make out a document that confirms Topsy is legally hers – an important step that protects Topsy from being sold after St. Clare’s tragic demise.
After Eva’s death, Ophelia has an open conversation with Topsy, in which she admits that she doesn’t love the girl yet, but she’ll work hard to change that. As a result, she wins Topsy over. Topsy becomes a pious, dedicated member of a Christian community in the North, and eventually a missionary.
Miss Ophelia functions in the story to demonstrate that the problem with slavery cannot be blamed on the South alone. The northern states play a part through prejudice, as well as by extraditing slaves through the Fugitive Slave Act. Ophelia also represents one form of religious practice – although she’s genuinely faithful, there’s too much strictness and not enough love in her philosophy.
From Stowe’s perspective, Miss Ophelia represents "the very best of Northern people" who are virtuous and hard working, who always do the right thing and keep a clean conscience but who, when it comes down to it, are kind of harsh and lack love (source, paragraph 51). Ophelia is a Christian, but not Christ-like the way that Tom and Eva are; that’s something she has to work on.
Miss Ophelia’s character also functions in the story in another important way, by demonstrating how slavery threatens women’s household concerns. According to scholar Gillian Brown, the scene where Miss Ophelia tries to set Marie St. Clare’s house in order is pivotal for understanding Stowe’s vision for a "right" universe. In Stowe’s world, slavery was wrong because it was an "outrage" on the family.
The waste in Dinah’s kitchen offends Miss Ophelia’s sense of a well-ordered household in much the same way that slavery offends her morality. For Ophelia, kitchens become a metaphor for social conditions in the North and South. northern kitchens, in Ophelia’s mind, are pictures of economy and cleanliness – just like the North’s moral stance on slavery. In the South, however, kitchens are disorganized and wasteful – just like slavery, which is ultimately destructive for all who are involved in it. In the character of Miss Ophelia, then, Stowe links the political sphere with the domestic sphere. If only government were more like housekeeping – not just doing chores, but managing household finances and an entire staff – the world would be a better place.