Wanjira is from the Kikuyu (Gĩkũyũ) Wanjira — one who travels, daughter of the road — from njira (road, path). Wanjira is one of the Kikuyu feminine names — central to traditional Kikuyu Bantu Indigenous Kenyan heritage. Kikuyu feminine name reflecting Kikuyu clan-naming tradition where children are named after paternal grandparents.
Wanjira 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 Wanjira reduce to 4, The Builder. This is a traditional interpretive system, not a factual claim about the name.