Hey, you figure, if it's what I really desire, I'll be happy with it no matter what it is...right? Besides, you know curiosity would get the better of you eventually. Picking up your wish ball, you grasp it tight and concentrate hard.
There's no flash of light, no breeze, no noticeable effect. Didn't it work? Nothing feels very different to you...You walk into the guest bathroom, where there's a full-length mirror, only to receive the shock of your life.
You've become a girl, for starters. Sixteen years old, curvy and moderately buxom, with long brown hair that falls partway down your back. You're beautiful, but there's more. Your ears are very different - they're on top of your head now, and they've become thin and triangular, with grey fur on the outside and white fur on the inside. Looking at your hands, you see that your fingernails are gone - you have retractable claws in their place. Your jaw drops open in surprise, and you note that your canines have grown into full-out fangs - the effect is very cute, really. Behind you swishes a slender tail, about three feet long, covered in the same grey fur as your ears. You're not just a girl, you're a cat-girl.
Your clothing has changed, too. Your blue jeans have remained blue, but the denim fabric has reshaped into a knee-length pleated skirt. Your red T-shirt has become a plain white blouse as well. Your underwear has changed too; you can tell that you're wearing a bra underneath your shirt, and your boxers have become snug-fitting panties with a hole in the back for your tail. Even your socks have changed - they've gone from the dirty gym socks you were wearing to clean, white knee-length socks.
This can't be right, can it? How could you have spent your life wanting to be a girl without knowing you wanted to be a girl? But...it does feel right, somehow. Maybe it just wasn't enough of an urgent need for you to notice it; wanting to be something else doesn't preclude enjoying what you are, you guess. You were happy as a guy, true, but...you're happier as a girl, as a cat-girl. Even now, having just changed, you're happier.
As you survey the new you, a peaceful smile forming on your face, the door to the bathroom opens and Danielle enters, now clothed in a denim jumper. "Kevin?" she squeals. "You're a girl now too? Oh, that's awesome!"
You smile, shaking your head. "Kevin..." you murmur. "No, I'm...I'm Carla now..."
"Okay, Carla!" Danielle smiles. "C'mon, we've got to show you to everybody else!"