Three short lines carry a small, quiet scene. The speaker has gone to a station to see someone off, and the poem hints that this person is a woman, since the title and the pronoun "her" point that way. The speaker has an "old hip," so they're slow, a little worn, perhaps leaning on that body as much as the moment. Then, in the middle of a farewell, they find a ring.
The poem never says whose ring it is or what it means, and that gap is where its feeling lives. A ring can suggest love, marriage, promise, or loss, and finding one at the very moment of parting makes all of those possibilities hover. Is it hers? Is it someone else's, dropped by chance? The speaker doesn't tell us.
The mood is gentle, wistful, and a little uncertain. The mention of age sits beside the ring's suggestion of commitment, and the poem simply lets the two meet without explanation.