Audrey comes from the Old English Æðelþryð (Aethelthryth), a compound of æðele (noble) and þryð (strength). The original Anglo-Saxon name was so difficult to pronounce in later centuries that it evolved through Etheldreda into the shorter, smoother Audrey.
Saint Audrey (Æthelthryth, 7th century) was an East Anglian princess who founded an abbey at Ely; the word "tawdry" derives from cheap lace sold at her annual fair. The actress Audrey Hepburn brought the name into modern consciousness — and by 2010 Audrey had climbed back into the U.S. top 50.
Audrey 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 Audrey reduce to 2, The Peacemaker. This is a traditional interpretive system, not a factual claim about the name.