...the feelings that came with her age changing ability were new to her still.
She glanced at her shirt and saw her nipples rising under the fabric. She reached and felt them much harder than ever before.
Her future breasts were already beginning to assume their outlines. She could feel them grow, slowly pushing her fingers away. Her hand crept along her tightening stomach, which was cramping but she couldn't care. Her panties were already sliding up over her widening hips, as her fingers slid along the tight skin where they had rested moments before. Her buttocks were becoming much more firm and rounder, and the protesting panties were becoming more like a g-string. She had probably gained five inches in height from her legs and abdomen so far. Her body was straining upward faster than it was increasing in width.
Her fingers, which were lengthening as she did this, slid into the top of her skirt, and just as she could feel new hairs materializing there as if by magic, the boy knocked on the door and said "Hey kiddo, you fall in?"
This broke her concentration and she watched in dismay as her body retreated downward in age. She breathed deeply as her breasts became small and vanished like a lost memory, her hands shrinking into their stubbier selves. Her shirt slouched into its regular position, but it was seriously stretched out.
Her skirt fit more or less right again, and she felt a chill between her legs. Her face thinned and her hair became short. She opened the bathroom door. "Don't call me kiddo!"
"Or what?" he mocked.
She stamped her foot. Already she could sense it took a moment longer to reach the floor.
In the first seconds her legs stretched wildly as they gained tone.
Her plain cloth sneakers bunched horribly as her feet grew several years’ worth in only moments. They just split down the middle and popped off in jagged pieces. A separated rubber sole slid across the room. She stumbled and almost fell at this point, balancing against the wall in front of the dazed boy.
The slightly baggy rainbow stockings she had been wearing split at the knees before they could slide all the way down her legs, her longer calves cramping painfully with her growth.
The skirt, which had withstood the partial aging earlier, now did not stand a chance as her teen thighs became almost twice as wide.
The seams were the first to go, but since it happened so quickly, they tore all over. Her white cotton panties did not survive either. The sudden thrust of her hips sideways, and her ass gaining twice its volume caused them to tear away at the sides, but the elastic band held, digging painfully into her skin.
The alteration of her ass caused her pelvis to thrust toward the amazed boy.
Jennie's would-be lover had been transfixed by the transformation of her upper body.
He noticed the girl's stomach slide smoothly from under her straining shirt.
He saw her sides curve toward the new hips below them.
Her right hand was in his peripheral vision and he saw the fingernails slide outward as her fingers warped into an adult shape. Her hands splayed as they grew knuckles, and the tendons expanded. Her abdomen bulged and pulsed as her developing breasts quickly pushed her shirt up her body. The shirt, already strained hard over her wider back, was having a poor time covering Jennie's B-cups. A back seam ripped so fast it sounded like a snap. All of the fabric had slid upwards, and now all the top buttons gave way. Her hard nipples practically tore through the shirt, leaving tatters of it stripped across two definitely adult-sized breasts.
The boy looked at her no longer innocent face.
A flushed, panting, wild-looking teenager was staring back at him. Her neck finished elongating, and he watched her jawline change, and even her lips as they swelled noticeably.
She pulled the boy closer, but he had already fainted.
She blew her tangled hair out of her face and awkwardly lowered him to the floor. She stood up and stretched, her hands trying to reach the ceiling. Tatters of clothing fell on top of the boy as he slowly regained consciousness. As he stumbled to his feet, he followed the long legs up the naked form of what had been a normal child less than a minute ago. The young beauty, her hands on her hips, was smiling down at him.