Fenella is the Scottish form of Finola — from the Irish Fionnuala ("white-shouldered" — fionn meaning fair + guala meaning shoulder).
Fenella 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 Fenella reduce to 1, The Leader. This is a traditional interpretive system, not a factual claim about the name.