Frankie sits next to 5 phonetic neighbors — Frannie, Franny, and Hattie are the closest matches by sound. Most share Frankie's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"free one"
"oath of God"
"wise"
"sun, throne"
"sparkle, glitter"
"to breathe, to live"
"God is my strength"
"supplanter, one who follows"
"to be of worth, to be strong"
"free person"
"shining light"
"birdlike, of the birds"
"sacred to Jove/Jupiter"
"stem, hollow reed"
"from the green valley"
"lovable, deserving of love"
"God is gracious + feminine suffix"
"gracious, dear, beloved"
"warrior, raider"
"spiritual gladness, divine blessing"
"Ceol's island, ship island"
Similar sound: These names share phonetic patterns with Frankie — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Latin (Francus) origins, giving them the same cultural heritage as Frankie.
Rhythm: Frankie is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.