Graham is from the Old English grand-hām (gravelly homestead) — historically a male Scottish surname now used as a unisex given name. Bob Graham — male; former Governor of Florida. Sir James Graham (1792-1861) — British politician.
Graham 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 Graham reduce to 3, The Communicator. This is a traditional interpretive system, not a factual claim about the name.