In just one line, the speaker describes a sacrifice. The "kingdom" stands for something that belongs to them alone: their independence, their place of power, maybe their sense of who they are. Handing it over so that "another person" can become queen suggests the speaker is willing to step aside, or even lose something important, so someone else can rise.
What makes the line interesting is how calm it sounds. There's no anger or loud complaint, just a plain statement. Still, the word "giving up" carries weight, and the phrase "just to let" hints at how much is being surrendered for what might seem like a small reason. The speaker could be feeling generous and loving, or quietly sad, or a mix of both.
The poem is also open to interpretation. It might be about romance, family, or friendship, and the title "kin" nudges us toward thinking about family or close bonds. The mood is tender but bittersweet, a little like watching someone make a sacrifice and wondering what it costs them.