As the warmth began in her body, Katie felt her swimsuit shifting and becoming smaller on a steadily growing body. Her arms and legs came first, growing out, long and gangly like the legs of a colt. Her fingers and toes became thinner, more distinct and dainty as the nails themselves became painted pink polish. She giggled and swung her legs and watched with fascination as her toes drifted further and further to the floor of the carpet, until the balls of her feet touched...then the flats, then the heels, She sighed in elation and realization that she was growing up, finally able to touch her feet to the floor of most places at last, though a part of her somehow wished she could swing her legs at times.
The coltish appearance stopped there though as she experienced something strange. Her hips began to push out, just a little bit at a time, gaining a slight curve, at the same time her legs and arms gained a distinct tone to them as if she'd spent every day running, playing and moving. Her stomach gurgled as it also flattened and toned nicely, and she could watch the change as it spread along her bare belly and along her belly button, leaving her abdomen neatly pretty like she'd seen girls who entered surfing competitions. The skin of the changed areas began to gain a natural and nice tan and she criss crossed her legs to see the pigment slowly change.
By now her bathing bottom had stretched beyond its limit and she felt a new strange tingling beneath it, she felt a warmth as within her insides her body began to approach the age of adolescence. She could not see the changes, but she distinctly felt them, letting out a little gasp as new thoughts and understands began to grow in her young preteen mind.
At the same time her flat tanktop would begin to swell with the growth of two small mounds beneath it, the same warmth below filling them as she began to develop...her eyes widening now as she understood what was happening.
"Im....entering puberty..."
The thought excited and terrified her and the changes werent done. She could see her face in the rearview mirror as the cute, childlike features began to define. Her button nose was still that, but it was starting to even out. The freckles on her face were less prevalent and her teeth rearranged as some adult ones grew in. She gained a certain maturity, a certain beginning of beauty as her hair began to flow long to her back and around her newly pierced ears. A prick and pain and looking down she found herself in possession of a third new one in her belly button, as if it has always been there. Finally her suit expanded and changed, becoming a floral print bikini for a girl like her age. Old, beat up and well loved converse sneakers tied themselves haphazarldy to her feet and a small childsized surfboard appeared next to her.
Katie could only watch and stare....feeling the change complete and realizing she was now finally a preteen.