Gisela of Lotharingia (757-810) was the daughter of Pepin the Short and sister of Charlemagne — abbess of Chelles, learned in Latin, who commissioned major Carolingian manuscripts.
Used widely in German-speaking Europe.
Gisela 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 Gisela reduce to 8, The Visionary. This is a traditional interpretive system, not a factual claim about the name.