Marianne sits next to 4 phonetic neighbors — Marion, Marian, and Marianna are the closest matches by sound. Most share Marianne's French-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"beloved grace"
"rose, beautiful flower"
"God saves"
"blonde, yellow-haired"
"female emperor, supreme ruler"
"from Brixton, the brick settlement"
"waterfall, lake"
"born on Christmas Day"
"grey lady"
"ship's victory"
"creative American coinage"
"God's gift"
"gift of Isis"
"lake meadow"
"yew tree; archer"
"sea of grace, beloved grace"
"Soft-haired, youth"
"God beholds, foresight"
"noble, of noble lineage"
"to esteem, to value (from aestimare)"
"grace, the gracious one"
Similar sound: These names share phonetic patterns with Marianne — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Hebrew via French combination of Marie and Anne origins, giving them the same cultural heritage as Marianne.
Rhythm: Marianne is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.