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).
Ember has been climbing in recent years. All-time it's been given to 23,072 U.S. babies, the 394th most common name by sound today, peaking at 2,222 in 2024, with 1,988 in 2025.
Ember has no common alternate spellings by sound.
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).