Whetū is the Maori word for "star." The Whetu Marama ("bright stars") of Matariki (the Pleiades) are central to the Maori new year celebration.
Whetu is widely used in New Zealand.
Whetu 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 Whetu reduce to 5, The Seeker. This is a traditional interpretive system, not a factual claim about the name.