You should have her hold him, when he's all balled up. Ball pythons are probably the least threatening snakes out there, and have cured many people of their fears.
Don't be afraid of being bitten. His natural reaction when you put your hand in will be to jerk back and hide his head. A strike occurs from a position where the neck is drawn back in an S, and the head is held elevated at high tension--you can actually see their little jaw muscles clench with the tension, lol. Ball pythons often jerk back with their neck in a low S defensively, and that shouldn't be confused for a strike position. He doesn't look very tense in your photos, so I doubt he's aggressive.