Marta sits next to 4 phonetic neighbors — Martha, Mara, and Marga are the closest matches by sound. Most share Marta's Spanish-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"mistress, lady, the lady of the house"
"bright one"
"God is gracious (via Gianna/Giovanni)"
"sky blue, azure color"
"bee"
"rose, beautiful flower"
"moon"
"illusion, magic, divine power"
"beautiful altar"
"dear little Ana, gracious one"
"song, poem"
"gentle, tender (linden tree)"
"illusion, divine power"
"lovable, dear, beloved"
"from the tower, elevated"
"ocean of nectar, divine gift"
"joyful (folk etymology via joy)"
"from Ávila"
"noble, of noble kind (if from Adal/Ali roots)"
"graceful lily"
Similar sound: These names share phonetic patterns with Marta — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Aramaic marta origins, giving them the same cultural heritage as Marta.
Rhythm: Marta is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.