Ellen sits next to 3 phonetic neighbors — Helen, Alan, and Ellan are the closest matches by sound. Most share Ellen's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"sun, moon"
"famous ruler"
"wealth, fortune, prosperity"
"called forth, gloriously summoned"
"Honor"
"he who follows at the heel; supplanter"
"resolute protector, will-helmet"
"princess, noblewoman"
"happy, carefree, joyous"
"servant of St. Fillan"
"botanical variant name"
"flat piece, thin layer"
"beloved, desired"
"gift of the ocean"
"hare's meadow, hare clearing"
"famous wolf"
"bright fame"
Similar sound: These names share phonetic patterns with Ellen — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek origins, giving them the same cultural heritage as Ellen.
Rhythm: Ellen is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.