There is no reference to another wife of Muhammad XI except Moraima. Sometimes, the historical figure strangely gets conflated in the legends about Sultanas purportedly loved by men of the Abencerrage clan, whose chieftains died by the order of Moraima's father-in-law Sultan Abu'l-Hasan Ali at some banquet twenty years before her union with Muhammad XI. By all accounts, theirs was a love match, whereas past Nasrids tended to marry royal cousins.
Readers of Sultana: The Pomegranate Tree, the preceding novel in which she first appears, will recall Moraima's unhappy state at the start of the marriage when her father-in-law Abu’l-Hasan Ali imprisons and separates her from her husband for a time. On her wedding day, Spanish historians described her as having been so poor, she borrowed simple wedding garments - quite unlikely since her father governed their birthplace of Loja, Spain by such time AND she was about to join the ruling family of a shrinking Moorish Spain. She's come down through history as a long-suffering woman, like the statue of her in Loja. She remains a sympathetic figure, never having been a queen in her own right. That's not quite true; when her husband reigned over Moorish Granada, she would have enjoyed a queenly status, although perhaps overshadowed by her mother-in-law, Sultana Aisha. As I've imagined her life in the new novel, she's no wilting wallflower content to remain in the background. Few women of the Nasrid Dynasty could afford to be. Not when life and death or the survival of the Moors affected their choices.