Ileana is the Romanian form of Helen. In Romanian folklore, Ileana Cosânzeana is the fairy princess heroine of countless Romanian fairy tales.
Princess Ileana of Romania (1909-1991) was the daughter of King Ferdinand I.
Ileana 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 Ileana reduce to 6, The Nurturer. This is a traditional interpretive system, not a factual claim about the name.