Christina is the Latin feminine of Christianus — "follower of Christ." Queen Christina of Sweden (1626-1689) — inherited the Swedish throne at age 6, abdicated at 27 to convert to Roman Catholicism, and lived the rest of her life in Rome as patron of artists and philosophers including Descartes (who died of pneumonia teaching her in cold Stockholm).
Subject of Greta Garbo's Queen Christina (1933 film).
Christina 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 Christina reduce to 2, The Peacemaker. This is a traditional interpretive system, not a factual claim about the name.