The title "She dwelt among the untrodden ways" makes me expect the poem to deal with a single woman who has a difficult life because nobody knows her.

The poem is divided into three stanzas; these have different number of lines (6-5-5).

The first stanza introduces the protagonist (a shy unloved girl)

In the second stanza the poet uses a metaphor and a simileto describe the girl

In the last stanza the makes clear that the girl is dead and he realizes that he misses her.

The most relevan  themes are "Nature" and "Feelings"; the poet uses nature to describes  the girl's qualities