Personally I think the major resolution of this great novel comes in Chapter 21 when Kit finally realises two things that the astute reader will have realised long before--she loves Nat and she loves New England. Clearly the two loves are linked, and as she reflects on the changing seasons of New England, each of which has its own beauty and delights, it is clear that her new home is linked inextricably with her feelings for Nat:
She did not want to leave this place, after all. Suppose she should never walk in the meadows again? Supposed she should never sit in the twilight with Mercy, or see Judith in the new house, or the girl Prudence would grow to be? Suppose she should never see Nat Eaton again?
Such musings force her to see the truth of her affections and also to recall some very wise words from Hannah Tupper:
"There is no escape if love is not there," Hannah had said. Had Hannah known when she herself had not even suspected? It was not escape that she had dreamed about, it was love. And love was Nat.
Thus is it that Kit experiences her final moment of self-knowledge in the novel. She realises that, instead of always thinking of Barbados as her home, that she has come to regard New England as her home with her family and her loved ones there, and she also has worked out that she truly loves Nat. This moment represents the final resolution of the novel as Kit knows her future and where it will take her.