Katherin sits next to 4 phonetic neighbors — Katherine, Catherine, and Kathryn are the closest matches by sound. Most share Katherin's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"pure"
"elf friend"
"lake, pool"
"flower garland, grace"
"bright, clear"
"work, industrious, vigorous"
"exalted, enlightened"
"precious green stone"
"modern melodic invented name, variant of Kehlani"
"enclosed garden, place of perfect happiness"
"from the hay hill, heath dweller"
"stag's woodland, forest clearing"
"shining grace, light and favor"
"modern invented name"
"God exists, gift of God"
"asked of God"
"gift from God (secondary folk etymology)"
"genuine, honest, pure"
"fairy lake"
"battle-alert"
"lioness of God"
Similar sound: These names share phonetic patterns with Katherin — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek origins, giving them the same cultural heritage as Katherin.
Rhythm: Katherin is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.