Marilynne is a 20th-century American elaboration of Marilyn — itself Mary (Hebrew Miryam, "beloved, star of the sea") + Lynn (Welsh "lake"). Marilynne Robinson (born 1943) — American novelist and essayist; her 1980 debut Housekeeping won the PEN/Hemingway Award; she then waited 24 years before publishing her second novel \Gilead\ (2004), which won the Pulitzer Prize for Fiction in 2005 and was named by The New York Times the best novel of the 21st century in their 2024 ranking of the century's books, drawing the vote of 503 literary figures. National Humanities Medal (2012).
Marilynne 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 Marilynne reduce to 3, The Communicator. This is a traditional interpretive system, not a factual claim about the name.