Rhea sits next to 5 phonetic neighbors — Ria, Freya, and Thea are the closest matches by sound. Most share Rhea's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"flowing, streaming"
"gracious judge"
"ascent, rising"
"Malay peninsula"
"protector of men"
"defender of men (from Alexandra)"
"my God is an oath"
"pure, clear"
"brave, courageous (lion-like)"
"divine radiance"
"one who mills grain"
"stem, hollow reed"
"heavenly flower"
"rest, comfort (when borrowing the male Noah's meaning)"
"father rejoices"
"bright fame, shining fame"
"song thrush, songbird"
"island of wild boars (alternative etymology)"
"sea ruler"
"of Mars, warlike"
Similar sound: These names share phonetic patterns with Rhea — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek origins, giving them the same cultural heritage as Rhea.
Rhythm: Rhea is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.