Sulwen is from the Welsh Sulwen — sul sun + gwen fair/white/blessed — fair sun, blessed-sun. Sulwen is one of the Welsh feminine names — central to traditional Welsh cultural heritage. Welsh feminine name reflecting Celtic Indigenous heritage.
Sulwen 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 Sulwen reduce to 4, The Builder. This is a traditional interpretive system, not a factual claim about the name.