She claims to support better lives for the Mrunas but she doesn't support equality for the black citizens of Maycomb. 

In To Kill a Mockingbird, Harper Lee uses the missionary circle meeting in Chapter 24 to expose the hypocrisies of many Christians in Maycomb. She does so by having the ladies at the meeting speak passionately about the needs of poor African tribes while also slandering African Americans in their own hometown. Characters like Mrs. Farrow speak of the prejudiced beliefs that all African Americans are immoral and inferior. Since people like Mrs. Farrow hold such beliefs, the same people also believe that Atticus made the wrong choice when he decided to put his all into defending Tom Robinson. Hence, when Mrs. Merriweather speaks of "good but misguided people," she is speaking of Atticus.

In Mrs. Merriweather's view, Atticus is a good person because he upholds his principles. In saying, "Might've looked like the right thing to do at the time," she is saying that she acknowledges Atticus tried to uphold his principles by doing what all good defense lawyers should do--defend a client. However, she also feels he made the wrong decision because the only thing his efforts accomplish was "stir 'em up," meaning make the African-American community aware of and protest against the social injustices heaped upon them. However, people like Mrs. Merriweather do not see mistreatment as social injustices; instead, she sees African Americans as being put in their rightful place of subordination. Therefore, she sees their protests as being nothing more than sulking and grumbling, as we see when she says, "[S]ulky ... dissatisfied ... I tell you if my Sophy'd kept it up another day I'd have let her go" (Ch. 24).

Hence, in her speech in Chapter 24, Mrs. Merriweather is accusing Atticus of having made a wrongful decision that led to nothing but trouble in the town because the African Americans began sulking, grumbling, and complaining about their treatment.