Rachel hand a thought, her endgame was to drain some age and swap places as the eldest sibling, but these muscles she had swapped would be hers regardless now, anything she added in her later years would be even more gain, would that work with other traits as well? What would happen if she took her sister's prized traits and then the age, would she gain even more? That would certainly add to the revenge for all the countless teasing she had suffered.
She was pretty confident she could overpower her sister now, especially if she gained a little height on her. As Stacy sat back down and sipped from her soda, hoping it would make her feel a little better, Rachel enacted her new plan. Using a jump scare in the movie as a cover, she "accidentally" spilled her soda on the couch and her sister's leg.
"Oh, my bad Stacy, the movie really got me there ha ha, ill get a rag and clean it, dont worry about it."
Stacy was annoyed and huffed in her frustration but didn't say much, she was still concerned with the oddly weak feeling she was having. Rachel returned and started to dry the spot on the couch and then offered to dab her sister's leg dry as well, not waiting on an answer she just started. In her mind she thought only of gaining height, butt, hips, and breast size from her sister. Rachel didn't really care if she noticed now, she was hoping she could at least gain a few inches before she noticed though, then she could rub it in as she took the rest, really hit home and put her sister in her place.
Rachel was 4 foot 8 inches no curves yet and Stacy was 5 foot 4 inches C cup, with a nice shapely butt, but that was all soon to change. As Rachel held the rag to her sister's leg she slowly inched upward, she could feel some tingling and knew it was working, but tried to use her crouched position to hide it as long as she could. Her shirt, already tighter from the muscles she had stolen was easy to tell the slightest change, as her chest slowly started to rise into two barely there mounds, and her pants were also starting to get tight as she added a couple inches of girth in hips and ass. She gained about 3 inches of height before Stacy felt the length of time she was drying her pants was starting to be very awkward and told her to stop and stood up to go to her room and change, but when she did she got slightly tripped up on the now too long pants. Rachel knowing she was going to notice sooner or later decided it was time and stood up to her new full height of 4 foot 11 inches, just 2 inches shy of her sister now.
Stacy was very startled when she got tripped up, she glanced down at her ill fitting clothes, "WTF happened here" she wondered aloud noticing the loose baggy jeans and even her bra felt a bit loose, plus she still felt that damn weak feeling, maybe even worse now that it seemed her clothes were weighing her down. She heard Rachel chuckle, "Heh, well you finally noticed I guess." She glanced back up to where her sister's face should have been only to be startled by what looked like an undersized shirt on a perky set of plump A (borderline B) cups, and her jaw dropped. "What the hell Rachel, when did you get boo... how did you get so ta... are you older? You look older."
"Oh I am not older, not yet. We will save the best for last, I am simply getting you back for all those times you made fun of me for being flat, or short. I am taking all those things you prize as my own, now come give your dear "little" sister a hug and lets finish what we started."
Stacy freaked out and tried to run, but her loose clothes betrayed her and she tripped face first into the floor. Rachel used this time to strip off her tight pants down to her panties, she didn't feel she could take much more and it might get distractedly uncomfortable, the shirt she could handle for now. Those out of the way she grabbed Stacy as she was trying to stand back up and pinned her to the wall. "Where you going sis? Don't you want to see the moment I surpass you as the "big" sister?"
Stacy struggled, it was almost a fight, but only for a second. Rachel had really underestimated how much difference even a couple inches could make, even with her muscles mostly drained, Stacy had the height advantage, albeit significantly less of one. Her strength did not last long though and she was firmly grasped by Rachel who was already draining more height, by the time Stacy realized struggling was useless their heights had evened out at 5 foot, and as she changed her tactics to pleading for her sister to stop, she could slowly see and feel as Rachel slowly grew taller than her, but only for a moment and it seemed to stop. Stacy was now 4 foot 11 inches and Rachel had stopped at 5 foot 1 inch, just enough to lord it over her sister, she would likely grow taller as she aged after all and didnt want to be too tall.
With her height and strength advantage secured, now it was time to savor the other changes... but what to do first? How could she rub this in her sister's face the most?