Not only Greek, but Greek descended by three centuries of inbreeding. There was almost no "outside blood" in that entire three century dynasty, it was all people descended from Greeks marrying other descendants of Greeks (the vast majority from inside the Ptolemaic dynasty itself).
And there exists contemporary depictions of what she looked like.
In fact, one of the rare incidents where they married somebody from outside is Apama II. A Princess from modern Libya, her family descends from Seleucus I Nicator, another of Alexander the Great's Generals. Or Cleopatra Selene of Syria, who was yet another offshoot of the Ptolemaic Dynasty that had moved to Syria to rule a century before she was brought back into the main dynasty (and married I want to say her second cousin).
It never ceases to amaze me how some try to rewrite history to suit their own racist beliefs. Not unlike the depictions of Jesus with blonde hair and blue eyes.