There is some confusion about this person's name. The majority of the online trees showed her name as Coya Huayllas or Inés Huayllas, but other sites show her name as Quispe Sisa or Anas Nusta. I think have finally sorted this all out. Her original given name was Quispe Sisa, with the family name of Yupanqui. She was the daughter of Emperor Huayna Cápac Yupanqui.

The 'Coya Huayllas' part is a title. The 'coya', also spelled 'quya', was a high priestess who was also a ruler. Her functional title might be 'Deputy Emperor' since she ruled in the Emperor’s absence or as the subordinate ruler of a territory in the Inca Empire. So Quispe Sisa was Coya of the territory surrounding Huaylas. On this website, in the interests of brevity, I have translated 'Coya Huayllas' as 'Queen of Huaylas'. The 'Anas Nusta' term is also a title designating high nobility.

Francisco Pizarro and Quispe Sisa were married in a ceremony. As best I can determine, it occurred in 1533. In late 1532, Atahualpa was imprisoned in Cajamarca by the Spaniards. He offered his young half-sister Quispe Sisa in marriage to Francisco Pizarro in the hope of securing his liberty and sealing a partnership. Of course, his hope was doomed, but Pizarro accepted the offer. Quispe Sisa was baptized as a Catholic and took the name Inés.

The marriage ceremony was Incan rather than Christian. Some historians refer to Quispe Sisa and her half-sister Cuxirimay Occlo (baptized as Angelina) as 'concubines' of Pizarro. In this case of Inés, this does not seem fair. In modern times, many countries are consistent in recognizing a marriage if the ceremony was valid under the laws in effect at the time of the marriage. In 1533, the Inca Empire was still the recognized authority, even though it was tottering. Therefore, the marriage ceremony should be considered valid, and Quispe Sisa a wife, not a concubine.