How to read the band →
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).
Penelope
Penelope climbed for decades and has been a steadily popular name ever since. All-time it's been given to 109,533 U.S. babies, the 95th most common name by sound today, peaking at 6,734 in 2019, with 6,225 in 2025.
Penelope has no common alternate spellings by sound.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).