Nafissatou is from the Wolof-Arabic Nafisatū — from the Arabic nafīsah (precious, valuable). Nafissatou is one of the Senegalese + Malian + Belgian-Senegalese feminine names. Belgian Sportswoman of the Year (multiple times).
Nafissatou does not currently appear in the US Social Security Administration's top 1,000 girls' names, so we don't publish a US rank or birth count for it. That says nothing about the name's standing elsewhere in the world — only that it sits outside the ranked US data we rely on.
In Pythagorean numerology the letters of Nafissatou reduce to 8, The Visionary. This is a traditional interpretive system, not a factual claim about the name.