In the last section of "Tintern Abbey," Wordsworth focuses on his sister, Dorothy. What does looking at Dorothy make him remember?
The speaker of Wordsworth's poem "Lines Composed a Few Miles Above Tintern Abbey" reminisces about his younger days while looking upon his sister; at the same time, he reflects on the trueness of Nature, who "never did betray / The heart that loved her." In these moments, the speaker remembers that he himself held dear his time in nature, when he wandered the woods and the cliffs and "this green pastoral landscape" and found great spiritual reward. Together, the speaker and his sister have shared time next to wild streams, for example, and the speaker explains that time in nature with his sister made his worship of Nature even more meaningful. Seeing his sister now reminds him both of their time together and of her ability to inspire in him a deeper appreciation of the natural world.
As a Romantic poet, Wordsworth revered nature and experiences of the sublime. In addition, childhood was particularly special to the Romantics, and Wordsworth and his sister Dorothy shared the experience of childhood together. All of these themes come together in this poem to make for a deeply personal reflection on life and family.
In this famous reflection on the delights of nature and how nature is capable of being the balm to our exhausted beings, Wordsworth focuses on his sister Dorothy, who is with him on his walk as he views the beauties of the countryside before him. Note the answer to your question that the poet gives:
My dear, dear Friend; and in thy voice I catch
The language of my former heart, and read
My former pleasures in the shooting lights
Of thy wild eyes. Oh! yet a little while
May I behold in thee what I was once...
Thus we can see that looking at his sister and her "wild eyes" makes him remember the way that he was before in his passionate youth and how he regarded nature then, which is something that he had already covered before earlier on in the poem. Regarding his sister thus helps him to recall how he was once, which emphasises how much he has changed in the interim.