Libby sits next to 4 phonetic neighbors — Lizzie, Lily, and Livvy are the closest matches by sound. Most share Libby's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"pledged to God, God is my oath"
"rye field"
"counsel + lake"
"little dear"
"elf ruler, ruler of supernatural beings"
"to ascend, exalted"
"dweller near the holly trees"
"child of heaven"
"might in battle"
"work, industrious, whole"
"lake remnants, from the lake land"
"pure, clean"
"mortal princess loved by Zeus (mythological)"
"safe, unharmed"
"sea"
"modern coined name, meaning unclear"
"my God is the Lord (via Hebrew Elijah)"
"gift of Isis"
"garden of holly"
"pearl of the water"
"joy, happiness, gladness"
Similar sound: These names share phonetic patterns with Libby — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Hebrew (via Elizabeth) origins, giving them the same cultural heritage as Libby.
Rhythm: Libby is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.