The daughter of Quicksilver and Crystal, she was named after the moon, having been born there.
The first child to be born to a mutant and Inhuman, the genetic markers denoting these subgroups in humanity supposedly "canceled out" in her, leaving her a normal human. While Quicksilver, aghast at the thought of having a flatscan, human, daughter, initially sought to expose her to the Inhumans' mutagenic Terrigen Mists, he was talked out of this by Gorgon and Karnak, impersonating Lockjaw to make their point. Years later, however, when Luna was six years old, Quicksilver was depowered by the Decimation of mutant-kind. Desperate to get his powers back, he exposed himself to the mists, and subsequently talked Luna into returning to Earth with him, where he exposed her to some collected mist too.