There was pleasure in the very sound of her voice. Like a many-stringed instrument, she turned her tongue easily to whatever dialect she would, and few indeed were the foreigners with whom she conversed through an interpreter, since she answered most of them in her own words, whether Ethiopian, Trogodyte, Hebrew, Arab, Syriac, Median or Parthian. The kings before her had not even had the patience to acquire Egyptian, and some had even been lacking in their Macedonian.
I imagine she would have access to tutors. But still, even being conversational in this many languages would be a major project.