Ornella was coined by the Italian writer Gabriele D'Annunzio (1863-1938) from ornello, the flowering ash tree.
Ornella Muti (born 1955) is the Italian actress.
Ornella 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 Ornella reduce to 5, The Seeker. This is a traditional interpretive system, not a factual claim about the name.