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).
Paula is now well below its former popularity. All-time it's been given to 281,769 U.S. babies, the 1,277th most common name by sound today, peaking at 10,183 in 1963, with 318 in 2025.
Paula has no common alternate spellings by sound.
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).