Solid line = floor (spellings that unambiguously belong to the group). Shaded band up to the dashed edge = ceiling (the most it could reach if every ambiguous spelling counted here).
Briella has been slowly declining from its former popularity. All-time it's been given to 15,051 U.S. babies, the 770th most common name by sound today, peaking at 1,259 in 2018, with 845 in 2025.
Briella has no common alternate spellings by sound.