Earlier quoted context omitted.
Why would they? She was of Greek origin, a descendant from Alexander’s general Ptolemy.
Her family had been in Egypt for 250 years, that's a long time for genetic admixture. Otoh, Continuing the tradition established by previous Egyptian dynasties, the Ptolemies engaged in inbreeding including sibling marriage, with many of the pharaohs being married to their siblings and often co-ruling with them. Ptolemy I Soter (305–282 BC) [... 20 people ...] Cleopatra VII Thea Philopator (51–30 BC) https://en.wikip…
But Egyptians themselves weren't black either. There was one black dynasty from Kush, but "indigenous" Egyptians themselves weren't black.