Romantic literature is typically thought to contain thoughts of grandeur regarding love. In fact, love has little to do with the Romantic period at all. While love may erupt in Romantic texts as a secondary theme, it is not one of the characteristics which define Romantic literature.
The characteristics typical of Romantic literature came about as a rebuttal to the preceding period (Realism or The Age of Reason). Therefore, the Romantic period explored emotion and intuition over reason. Romantics also explored the importance of nature and imagination.
As for Wordsworth's poem "She dwelt among the untrodden ways", this text exemplifies the Romantic genre by highlighting nature: "springs of Dove" and "a violet by a mossy stone". Not only does Wordsworth use nature to exemplify the Romantic qualities of the poem, he also focuses on the feeling of the poem. (Here is where many believe that the theme of love is necessary to make a text Romantic- simplistically it is emotion which signifies Romanticism not only love). While Wordsworth's poem is not about love, one could interpret that he is feeling the loss of one who could have been loved.
Wordsworth is using his imagination to understand why the woman in the poem has lived a life alone, "among the untrodden path". The description of her life is one of solitude and beauty. Wordsworth seems to simply be focusing on those ideals and the fact that she should have been known by others.