Grace Merriweather demonstrates hypocrisy when she cares about the Mrunas but not the Robinsons.
Scout sarcastically comments “Aunt Alexandra and her missionary circle were fighting the good fight all over the house.” This is clearly an editorial comment from the older Scout looking back.
From the kitchen, I heard Mrs. Grace Merriweather giving a report in the livingroom on the squalid lives of the Mrunas, it sounded like to me. (CH 24)
As it turns out, Mrs. Merriweather could not care less about Helen Robinson or any of the other colored people in her town or employ. She is hypocritical because she cares about suffering in Africa, but not in her own backyard. She pretends to be a good Christian woman, but in fact she is just acting like she cares because it's fashionable. Even as a child, Scout seems to appreciate this.