Efua is from the Akan Afua — the Akan day-name for a female child born on Friday. Sutherland Children's Park in Accra is named in her honor.
Efua 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 Efua reduce to 6, The Nurturer. This is a traditional interpretive system, not a factual claim about the name.