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).
Mariana has been climbing in recent years. All-time it's been given to 45,972 U.S. babies, the 559th most common name by sound today, peaking at 2,069 in 2005, with 1,192 in 2025.
Mariana has no common alternate spellings by sound. Spellings sometimes heard the same way: Marianna.
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).