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).
Elizabeth is down from its peak but still widely used. All-time it's been given to 1,693,973 U.S. babies, the 76th most common name by sound today, peaking at 20,841 in 1990, with 6,765 in 2025.
Elizabeth has no common alternate spellings by sound. Spellings sometimes heard the same way: Elisabeth.
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).