The name reached its all-time peak in 2015 with 5 births ranking #12156. STABLE Recent data shows the name is currently stable.
Alayna is a modern spelling variant of Alaina. It sits within the Alan family of names, so its broader meaning follows that family rather than coming from a separate root of its own.
This kind of respelling became more common as parents looked for familiar sounds with a slightly fresher look. As with Alaina, the deeper history leads back to Alan, whose earliest etymology is not fully settled.