The main character is a boy whose mother is killed because another child is being born and their population numbers are strictly controlled. I remember a quote from the ritual that takes place: "Life come, life go," repeated over and over. He runs away, and meets up with another child/teen, a girl. She makes songs, and I can't quite remember the names...but the quote I remember in a song she makes up: "(name) run, (name) jump, in the lightest of light." I want to say the name was something like Fernfeather?
1 Answer
I'm going to suggest this is Roger Elridge's "Shadow of the Gloom-World" (1978). The protagonist is indeed named Fernfeather. The story takes place in a subterranean shelter in a post-apocalypse world. The other girl he meets up with after running away is named Harebell.
Here is a summary Goodreads:
"Fernfeather is the oldest son of a family of seven, but is weak and absentminded, and despised for his dreaming by the cavern-dwelling "folk" he lives among. Numbering 250, the folk live practical lives and do not believe there is anything beyond the cave they live in. They are ruled by the Vigilants, 5 elders permitted to live much longer than the folk, who go to the Chamber of the Long Sleep to die as soon as their strength begins to fail. The Vigilants in turn serve the Olden, a never-seen group which guides the folk from their sanctum separate from the cave of the folk, and are the only ones permitted to know the deeper mysteries of the world, such as how the glowing stones of the cave maintain a cycle of day and night."