Marguerite is the French form of Margaret — from the Greek margaritēs, meaning "pearl." The marguerite daisy is named for the saint. Marguerite Duras (1914-1996) wrote The Lover; Marguerite Yourcenar (1903-1987) was the first woman elected to the Académie française.
Marguerite peaked at #176 in the U.S. in 1898 and is rising again in modern naming.
Marguerite 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 Marguerite reduce to 9, The Giver. This is a traditional interpretive system, not a factual claim about the name.