Pemberton is from the Old English place name in Lancashire — Pem's town. Dr. Pemberley — Mr. Pemberton, British Columbia — Canadian community. Pemberton Mill — historic Lawrence MA. John Henry Pemberton — modern American figure.
Pemberton 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 Pemberton reduce to 9, The Giver. This is a traditional interpretive system, not a factual claim about the name.