The name reached its all-time peak in 2016 with 10 births ranking #7868. STABLE Recent data shows the name is currently stable.
Kaia is more specific than the earlier broad draft suggested. Behind the Name treats it primarily as a Norwegian and Estonian diminutive of Katarina or Katariina, which places it in the wider Katherine family.
Modern international use has given Kaia a wider feel, but the sourced route on Behind the Name is Scandinavian and Baltic rather than a loose mix of unrelated meanings. That gives the name a clearer home tradition and helps tighten the entry.