In the scene you quote, JA is describing Anne's pleasures, rather than directly expressing her own thoughts. And then she undercuts Anne again by bringing in the practical farmer and the inevitable turning of the years. I think Anne's flaw is a tendency to romanticism (she learned romance as she grew older), a very mild flaw, but one that JA teases occasionally.

Anne is thinking: unless some tender sonnet, fraught with the apt analogy of the declining year, with declining happiness, and the images of youth, and hope, and spring, all gone together, blessed her memory.

And then the next paragraph includes the following contrast:

...where the ploughs at work and the fresh-made path spoke the farmer counteracting the sweets of poetical despondence, and meaning to have spring again, ...