Jimena is the Spanish feminine of Jimeno, possibly from Basque seme (son). Jimena Díaz (c. 1054-c. 1115) was the Asturian noblewoman, wife of El Cid (Rodrigo Díaz de Vivar) — she ruled Valencia for three years after his death.
Jimena 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 Jimena reduce to 7, The Seeker. This is a traditional interpretive system, not a factual claim about the name.