I believe that sources inside and outside of the game state outright that only women can become Sorceresses.

Like I said, the Sorceress Power appears to allow a sorceress to alter her body in various ways. I wouldn't be surprised if Adel simply used her powers to take on a more masculine and giantess appearance to intimidate her population, but the game gives us so little information about Adel and her personality that it is impossible to say for sure.