Kelly sits next to 4 phonetic neighbors — Kelley, Kelli, and Kellie are the closest matches by sound. Most share Kelly's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"frequenter of churches"
"bright green gemstone"
"God is gracious"
"strong, healthy"
"flat tropical grassland"
"night"
"modern invented name"
"renowned in battle"
"diminutive of Margaret"
"hunter, game keeper"
"lake, body of water"
"scholar"
"mountain of whiteness"
"grace, favor"
"white, fair, pure, blessed"
"pleasant meadow"
"beloved, little Mary"
"honor (from Honoria)"
"mountainous, of the mountains"
"elf ruler, ruler of supernatural beings"
"sunlight, moon (alternate etymology)"
Similar sound: These names share phonetic patterns with Kelly — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Irish Gaelic origins, giving them the same cultural heritage as Kelly.
Rhythm: Kelly is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.