Sor Juana — "Sister Juana" — was the religious title of Juana Inés de la Cruz (1648-1695), the greatest poet and intellectual of Spanish colonial America. Her Respuesta a Sor Filotea (1691) is the first feminist tract written in the Americas, defending women's right to learning.
On the Mexican 200-peso bill.
Sor Juana 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 Sor Juana reduce to 9, The Giver. This is a traditional interpretive system, not a factual claim about the name.