Yardena is from the Hebrew יַרְדֵּנָה (Yardēnāh — descender, to flow down) — feminine of Yarden (Jordan) from Hebrew yarad (to descend). Yardena is one of the Hebrew feminine names — central to traditional Jewish + Israeli heritage.
Yardena 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 Yardena reduce to 5, The Seeker. This is a traditional interpretive system, not a factual claim about the name.