Brie is from the French region Brie (east of Paris, the home of Brie cheese since the 8th century) — also from the Irish Brigh (strength), a short form of Brianna or Brigid. The Brie Cheese Appellation d'Origine Protégée has covered Brie since 1980. Brie, as a given name, has charted in the US since 2007.
Brie 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 Brie reduce to 7, The Seeker. This is a traditional interpretive system, not a factual claim about the name.