Begga is from the Old Germanic baga (strife). Saint Begga (c. 615-693) was the Frankish noblewoman, daughter of Pepin of Landen and Itta, sister of Saint Gertrude of Nivelles. Her son was Pepin of Herstal, founder of the Carolingian dynasty — making her the great-great-grandmother of Charlemagne. Founded the monastery of Andenne.
Featured in Carolingian chronicles.
Begga 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 Begga reduce to 4, The Builder. This is a traditional interpretive system, not a factual claim about the name.