Gretchen sits next to 5 phonetic neighbors — Greta, Heidi, and Kirsten are the closest matches by sound. Most share Gretchen's German-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"pearl"
"graceful clearing"
"of God, elevated"
"descendant of Angus"
"honor, glory"
"glory of the father"
"lively, spirited"
"royalty, high chief (from lani)"
"deep valley dwellers"
"sun-like, radiant"
"crooked nose, bent nose"
"son of David, beloved"
"beautiful, lovely"
"grey land, rocky ground"
"whole, universal"
"heaven (spelled backward)"
"purity, innocence"
"modern American creation; jade-colored stone"
"blooming, young green shoot"
"woodland clearing, meadow"
"to flourish, to bloom"
Similar sound: These names share phonetic patterns with Gretchen — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek via Latin (via Margaret) origins, giving them the same cultural heritage as Gretchen.
Rhythm: Gretchen is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.