Antonina is from the Polish Antonina — feminine of Antoni from Latin Antonius. Antonina is one of the Polish feminine names — central to traditional Polish + Italian Catholic heritage.
Antonina 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 Antonina reduce to 7, The Seeker. This is a traditional interpretive system, not a factual claim about the name.