Wilhelmina is the German feminine of Wilhelm (William) — from wil (will, desire) and helm (helmet, protection) — meaning "resolute protector."
Today Wilhelmina is returning as part of the broader vintage revival.
Wilhelmina 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 Wilhelmina reduce to 7, The Seeker. This is a traditional interpretive system, not a factual claim about the name.