Valerie comes from the Latin Valeria, feminine of the Roman family name Valerius — from valere, meaning "to be strong" or "to be healthy." Saint Valeria (1st century) was an early Christian martyr.
Valerie was popular in the early 20th century and rose strongly in the 1950s-1970s, peaking at #94 in 1976. After a long decline it is climbing again, currently sitting in the U.S. top 200.
Valerie 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 Valerie reduce to 9, The Giver. This is a traditional interpretive system, not a factual claim about the name.