Sparrow is from the Old English spearwa — the small bird known for resourcefulness and ubiquity. The biblical sparrows in Matthew 10:29 ("Are not two sparrows sold for a penny?
Sparrow 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 Sparrow reduce to 2, The Peacemaker. This is a traditional interpretive system, not a factual claim about the name.