When you opened the package, you found a set of instructions. They informed you that inside the box were highly powerful potions which could transform the drinker in many ways. They would never run out.
You began examining the potions, which were divided into male and female. The main potions you saw involved aging and un-aging, height increase or decrease, raising and lowering sexual attractiveness, initiating or reversing puberty, and muscle growth or shrinkage. Some were gender-specific, like breast size or package size.
You decided to use your younger siblings as test subjects. When dinnertime came, you mixed some of each potion into their drinks. You gave Jamie female raised attractiveness, Danny male muscle, Christy female height increase, Michael male puberty starter, and Alex male aging. You might have gotten a little carried away on some of the dosages, but that was mostly because the potions came out so fast.
None of the kids seemed to notice anything off with their drinks. Jamie was the first one you noticed changing. Her dirty blond hair was turning straight blond and growing longer, her face became cuter, her breasts grew some, her legs became shapely. Clearly in a few years she would be a bombshell. She seemed to be making faces as she felt the changes, not realizing what was happening, but stopped when they did without noticing.
The other kids were too occupied with their own changes to inform her of her own. Danny's muscles were growing at a rapid rate. His biceps had swelled to strain his sleeves, his pecs shoved his shirt out further, and the rest of it clung to his new six-pack abs. Soon the shirt exploded under the stress, leaving Danny's muscular torso on display.
Christy was also having clothing problems. She was shooting up in height from 3'10 to 5'10 and wasn't stopping yet. Her pants were riding up to her thighs and her shirt exposed her stomach. She did finally stop at 6'4".
Michael had changes including those as his 5-year-old body launched into an early puberty. His penis grew to a respectable size (bigger than yours) and so did his genitals. The testosterone flood led to Michael growing 2 1/2 feet taller, gaining 100 pounds of muscle and a deeper voice, growing blond body hair in many places and a light beard on his face. He looked like a grown man.
Alex was rapidly growing up. No longer a toddler, he passed through childhood and tweendom and almost through the teen years, stopping at 18. By then he was a handsome black-haired beefcake of a boy.
All of the kids were confused and it was quickly becoming chaotic. What would you do?