She is skeptical because John goes out to plow his field on Sundays. On Sundays it was critical to attend church. It was uncommon for someone not to attend church and at the time many people were accused of being linked with the devil. Elizabeth Proctor began to think this of John.
<span>In Chapter 2, the author comments that the fate of Ikemefuna is a "sad story" that is "still told in Umuofia unto this day."
So Okonkwo tells his sons sad stories</span>
I think it's the first one. Throughout the story we see Becky struggling with the idea that she might fail this time. Really she is making the possible outcome seem worse than it actually is (the outcome being that she could fail the test again), and Justin helps her calm down and realize that it really isn't that big of a deal if she doesn't pass.