I didnt like that dialogues of Zoya...Muslims do not defy or challenge God...It was a bit contradicting..to see her on one hand praying to Allah to let her Aunt Live and on the other hand challenge Allah like that...her sentence was implying that she will Defeat Allah..which is really not in our religion...like you have said...in Islam we grow to believe that Allah has our best interest in whatever happens in our life.
But I took it as a moment of weakness from the character...Because it happened right after Asad hur her with her mom thing..so she was shaken...and all humans have moments and phases of weakness.