Abishag (אֲבִישַׁג) means "my father wandered" in Hebrew. In 1 Kings 1:3, Abishag the Shunammite was the beautiful young woman brought to comfort the aged King David in his final days.
Abishag 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 Abishag reduce to 2, The Peacemaker. This is a traditional interpretive system, not a factual claim about the name.