Chuckle, don't think we are going to get to use this move, in a Legal Game that is!
The 2 square optional move, when the Pawn is on its original square only applys to the Pawn moving Forward. Forward in this sense of the word means straight. Diagonal is not straight (like an off ramp on the freeway:) and tho the Pawn can be seen as moving forward( in an overall sense) it is taking a diagonal direction in the process of moving forward. And when it takes a diagonal direction then the Pawn does not have the option of taking a 2 square move.
The Queen is safe! And my hubby is most impressed with your 5 ( at the time) daughter for having the ability to discern this possibility at such a young age. ( boy are you in for it with this one :)))) He's been playing since 9, taught by his father and it has remained one of his most cherished memories.
Does this clear it up?
All the best to you and 'the gals'.