Isadora is from the Greek Isidoros ("gift of Isis," the Egyptian goddess of magic and motherhood) — used as a Christian-era given name across Byzantium and the Mediterranean. Her autobiography My Life (1927) is among the most-read dance memoirs of the 20th century. Isadora Bing — Friends recurring character. Isadora Smackle — Girl Meets World. Saint Isidora of Egypt — 4th-century Coptic Christian.
Isadora is a compound name. Its parts are dōron — each an attested element with a recorded meaning of its own.
Isadora 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 Isadora reduce to 4, The Builder. This is a traditional interpretive system, not a factual claim about the name.