Hadewijch of Brabant (13th c.) was the Flemish Beguine mystic and poet — one of the writers of vernacular Dutch literature.
Featured in modern anthologies of medieval women mystics.
Hadewijch 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 Hadewijch reduce to 8, The Visionary. This is a traditional interpretive system, not a factual claim about the name.