Aoife is one of the most popular girl names in Ireland and has been for three decades. Outside Ireland the spelling — and its pronunciation, EE-fah — is the chief barrier to wider use, but its sound is gentle and the meaning unambiguous.
Aoife 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 Aoife reduce to 9, The Giver. This is a traditional interpretive system, not a factual claim about the name.