Pure
Kaytlin is a modern phonetic spelling of Caitlin, the Irish form of Catherine. It ultimately derives from the Greek name Aikaterine, which is widely associated with the concept of purity.
Less common today
Kaytlin isn't in the latest US Top 1000. It last peaked at #1,019 in 1999.
US births per 5-year period, 1990βpresent (SSA data).