Sunshine sits next to 3 phonetic neighbors — Sunny, Sunni, and Sunflower are the closest matches by sound. Most share Sunshine's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"light and warmth from the sun"
"rival, striving"
"rose"
"gracious lake, graceful waterfall"
"whirlwind, storm wind"
"high tower"
"delight, gladness"
"from the north, northman"
"star"
"battle king"
"farmstead near a church"
"earth, land, soil"
"Jehovah has been gracious"
"upper class landowners (social class)"
"illumination, radiance"
"may God protect"
"heavenly flower garland"
"whole, universal (Emma) + meadow (Lee)"
"symbol of peace and wisdom"
"raven island"
"happy, fortunate, blessed"
Similar sound: These names share phonetic patterns with Sunshine — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old English origins, giving them the same cultural heritage as Sunshine.
Rhythm: Sunshine is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.