Child of Earth & Sky by Praag, Menna van;

Long description:

Born of bright-white wishing and black-edged desire, the Grimm girls each command a single element and wield it with great power. But a child born of a Grimm and a fallen star will have command over every element . . . and wield infinite power.

At twenty-one, Goldie gave birth to a daughter by her dead lover. Now Goldie is nearly thirty and Luna almost nine. Conceived in the realm between life and death, Luna is part star-soldier, part Grimm and now those opposing forces are waging war within her.

Terrified of losing her increasingly volatile child, Goldie goes on the run. Then an act of violence forces her to return and Luna is taken into care. Mother and child can still meet - in the haunted otherworld that is Everwhere.

Desperate to reclaim her daughter, Goldie must also confront whatever is corrupting Everwhere. For fresh leaves are falling, and Grimm girls are dying. Fearing the return of her father, Goldie knows she cannot succeed alone and summons her sisters.

But can the bonds of sisterhood bear the terrible price that will be paid . . .