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).
Kaylee has dropped sharply from its peak but is still widely used. All-time it's been given to 336,926 U.S. babies, the 204th most common name by sound today, peaking at 15,039 in 2009, with 2,977 in 2025.
By sound, Kaylee also includes the spellings Kayleigh, Kailey, Kaylie, Kaleigh, Kaley, Kailee, Caylee, Kayley, Kayli, Caleigh, Keily, Kalie, Kalee, Cailey, Kaeli, Kaylea, Kaili, Kaileigh, Caley, Kaily, Cayleigh.