I had nothing in harmony with Mrs. Reed or her children ...

What did Jane discover?

A.

Jane discovers Mrs. Reed is not such a bad person.

B.

Jane discovers she is different from Mrs. Reed.

C.

Jane discovers she is intelligent.

D.

Jane discovers it is better to get along with everyone.

I believe the correct answer is B. Jane discovers she is different from Mrs. Reed.

The way I interpret her phrase 'I had nothing in harmony with ... ' is that it means that she had nothing in common with those people, she didn't really get along well with them, and that she is completely at odds with such people, which is why I'd choose option B.