If I may suggest, I was thinking of three mini cutscenes. The least amount of objects is where he gets turned back into a boy and tells his buddies to not go in there.
If you collected optional items, it's the ending you have now and maybe a bit of dialogue with his friends.
And if you collected everything, she immediately rejects the offer of being turned back.
With maybe an ending image of he/her new life. That is what I was thinking of. I still loved the game and I also played your other games too!