Morwenna is a Cornish name from the Welsh morwyn, meaning "maiden." Saint Morwenna was a 5th-century Cornish saint; the village of Morwenstow in Cornwall bears her name.
Morwenna is rising in Cornwall and the UK.
Morwenna 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 Morwenna reduce to 4, The Builder. This is a traditional interpretive system, not a factual claim about the name.