As Chris slept she had dreams of what the necklace might do to her. It wouldn't change her into a male, and that made sense, to do so would require swapping out a whole chromosome. That was a big change. But if it would change her then there was some level of change that wasn't too big. Some level of DNA it was willing to switch out. If it made a little change here and a little change there that could add up to something big. It could make her into a completely different person. More than that, it could make it so she wasn't a person anymore.
Chris had dreams of being all kinds of strange things, things that didn't look even remotely human, some of them were beautiful, but there were also nightmares of the horrible things she might become. Would she become a hideous monster incapable of thought?
While Chris' unconscious mind raced, the necklace did its work. It grew brighter, but not near the blinding light it had shone before. The first changes were not heavy handed, as if the necklace chose to demonstrate what it could do with subtlety rather than force. As before the hair was the first to change, the brown lightened and a hint of red crept in. It became a bit less straight, and a bit more wavy.
Then her tan became a bit darker, muscles grew a bit stronger, a bit firmer, they remained sleek, maintaining her feminine image. Her eyelashes a bit longer, her face a bit longer, her nose a bit longer, her lips a bit fuller. Her breasts were next, they slowly expanded until she gained a cup size, her nipples lengthened and aureoles widened.
Next her entire body lengthened, her torso, arms and legs all grew longer. As her bones grew they lightened. Her entire body became lighter than it had been before. Some of her shed pounds were regained as her hips and thighs gained some fat to remain proportional but overall she became lighter.
In a small shimmer of light, the plain white tank top altered itself, creating additional holes but remaining largely the same.
Then the necklace abandoned subtlety, seemingly deciding that this was the time to shine. New bones formed on Chris' back they extended outward through the holes in her tank top and formed into limbs longer than her arms. Slowly something white began to push out them, at first they seemed like little hairs and they seemed to form a white fur on the limbs, but they did not stop there. They continued to grow and formed into feathers. When the feathers finished growing Chris looked like a classical depiction of an angel.
In the morning Chris awoke with a start, having just finished a nightmare where she was transformed into a mindless werewolf like creature. She felt herself, no fur. As she pulled herself out of bed, everything felt normal so far. Her breasts were in the right place, she definitely seemed human. She felt light on her feet as she walked to her dresser. When she looked in the mirror the first thing she noticed was her eyes, they were lavender now. What she noticed next was that the cumulative effect of all the little changes made her look older, in her mid 20s rather than 17. She started noticing the other changes. Somehow she knew that the necklace had changed every one of the things it could change, but not nearly as much as it could change them. She'd have to ask Alex what size breasts she liked.
After some of the dreams she had had she was happy to find herself still human. Her mind hadn't been changed, and she took that at as a sign that the necklace couldn't, or wouldn't, change her mind. She guessed that it could adjust her features, but not actually replace them with other versions. Hence the lack of fur. So she could theoretically look like any kind of human female, but only a human female.
That's when she noticed her wings. Eventually she would add an addendum to her assessment (adding limbs works too! They don't even have to be human) but for now she was awestruck. Moments ago she had been happy to be human, now she was ecstatic that she wasn't. She felt her wings, they were soft, comforting. They were also strong. She flapped, and believed she could fly. Her room wasn't all that tall, not much space to fly, but she was determined to see if she could stay in the air and, after much frantic flapping, she did.
Life was good. She couldn't wait to show Alex.