Antoinette is the French feminine of Antoine — from the Latin Antonius (a Roman gens name of uncertain meaning, traditionally interpreted as "priceless, praiseworthy"). The apocryphal "let them eat cake" line was never actually said by her — the phrase appears in Rousseau's Confessions (1782) about "a great princess" written when Antoinette was 9 and living in Austria. Antoinette Perry (1888-1946) — American actress, director, and producer; co-founder of the American Theatre Wing; the Tony Awards (officially the Antoinette Perry Awards for Excellence in Broadway Theatre, since 1947) are named in her honor. Antoinette Robertson (Dear White People).
Antoinette 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 Antoinette reduce to 6, The Nurturer. This is a traditional interpretive system, not a factual claim about the name.