Before his eyes, Jack's body started to change in a way he'd imagined for a long time. Since he'd first found out that the odds of someone being born male or female were functionally a coin toss, he'd wondered, 'what if it went the other way?...' He still remembered the day in class they'd been taught that when developing in the womb, the body either gets a genetic stimulus at a certain point or does not, which causes it to develop either male or female, and he'd wondered what he'd be like if his body had never received that stimulus.
At last he got to find out. The girl was right- this felt so good. He wondered, was this what taking the green pill instead of the red one in that one sci-fi movie he watched a while ago was like? It sure felt like it- like his body was waking up to the possibility that this wasn't how it had to be. The magic of the wing had opened up 'the other way' to him, and the signs of it had already begun to emerge. His face seemed different, his skin softer, jawline smoother, cheeks larger, lips puffier. His Adam's apple receded inwards, giving him a higher-pitched voice.
The changes rapidly ran down his body, ignoring the most obvious places for a moment. His shoulders narrowed and his hips widened, and his stomach and chest slimmed, giving him an hourglass figure. His butt enlarged and his arms and legs grew thinner and more lithe, while his hands and feet shrank slightly in proportion. With his figure adjusted and an intense tension brewing in his chest and crotch, at last the most obvious changes came to fruition. Suddenly he realized his nipples felt sensitive. Way more sensitive. And before his eyes they started to grow larger and puffier, and the flesh around them was budding and enlarging. He had A-cup breasts, and soon they had enlarged to C-cups.
The last vestige of Jack lay between his (now smooth) legs, and as it vanished, so did her feelings of masculinity. His penis shrank into her crotch rapidly, growing more and more sensitive as it grew small, while his balls moved up inside her, and his scrotum became flush with her crotch and stretched as it was reshaped into labial lips. Soon his penis had receded into her clitoris with the former shaft as its hood, and a vaginal opening had formed between her legs.
Once she recovered, Jackie Folders looked at herself in the mirror in amazement. For so long she'd thought this was impossible, no matter how much she wished it could happen. She had totally transformed herself from a boy to a girl. She was the same person, and yet someone totally different.
Smiling, she wondered what to do with her new body.