Liiza was the daughter of the ambassador managing the relationship with the human species. She has always been vague about her father, and Khan didn't probe further due to the obvious internal problems in her family. Still, she clearly was a privileged figure in the Niqols' society.
Paul didn't tell Khan to consider her as a princess by chance. His statement had reasons that involved her social importance for both species. Liiza was an untouchable figure for the human species and a coveted political partner for the Niqols.
Khan didn't feel strange to learn that Liiza was part of one of the most famous academies on Nitis. Still, he remained speechless when she confirmed that her school had been the one accepting the humans. The couple would have to attend lessons in the same structure, even if they were different since she was already in the second year.