About the blackwashing and the historical sources
It seems that the black chick is based in an historical character named 'Catalina'*. She was a Moorish slave assigned to Catalina de Aragon and became one of the 60 servants that traveled with her to England. Her ethnicity is unknown, she could have been Arab or Black**.
https://www.historytoday.com/history-matters/other-catalina
After her manumission, she would marry a Moor cross-bow maker named 'Oviedo'. Ethnicity unknown, though he was probably Arab (just a matter of probability).
So that was it. Hollywood singled out this one out of the 60 servants and made her a main character. Then they brought Oviedo and made him black, and put him near to the princess, which is total nonsense: after a war with the Moors, you place a free Moor armed with weapons besides a member of the Royal Family. What could go wrong?
And then some.
Here there's a pic
https://m.media-amazon.com/images/M/MV5BYmJkNmEwOTYtMDYwMC00NjI3LWJmZDctNjkwYzhjZjZjZjEwXkEyXkFqcGdeQXVyNjg2NTgwMDc@._V1_.jpg
Hollywood got a slave that could have been Arab or Black, among the 60 servants of princess Catalina, and ended up having half of the characters in the plane where the princess lands in England being black...
When the House Tyrell of Game of Thrones looks closer to the Spanish Court than your supposedly accurate historical series... well...
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*Sometimes she's called 'Catalina de Cardona', but that's wrong, Catalina de Cardonas was a different person: https://es.wikipedia.org/wiki/Catalina_de_Cardona
**She was compared to a black pygmy, and that's all what we know about it. But comparing Arabs to Blacks was a frequent insult back then. The term 'Moor' itself means black, and it was often used as an insult. Nowadays, it would be labeled as the 'M-word'.
However, the height's clear: she must have been short.