Bertilla sits next to 5 phonetic neighbors — Bertille, Camilla, and Priscilla are the closest matches by sound. Most share Bertilla's Italian-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"bright, famous"
"son of Neil"
"all-wise, all-knowing"
"gift of God"
"goddess of flowers and spring"
"flower, bloom"
"fertile plain (if derived from Sharon)"
"from Lorraine (kingdom of Lothair)"
"famous in battle, glorious warrior maiden"
"bright, shining"
"all true, entirely faithful"
"elf battle, elf warrior"
"noble friend"
Similar sound: These names share phonetic patterns with Bertilla — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Germanic origins, giving them the same cultural heritage as Bertilla.
Rhythm: Bertilla is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.