Amy thought for a moment and asked "Since we're on the topic of clothes, could you get me some new duds before we head home." the eight year old said.
"If you say so dear..." the 49 year old replied as she got the car more into motion as they made a b-line to the department store. By the time they arrived a few minutes later the 57 years of age between the two of the girls had been split a bit more evenly. The 12 year old trying to cover her chest which between her clothes that were not meant for someone several years younger than her. "Alright, I'll be buying something with Grubhub and you have til its arrival to find something that'd fit you and your budget. What would you like?"
"I'll have a quarter pounder meal with a coke." Amy said as her breasts swelled underneath her top which she was trying to hide, a little exacerbated about how her niece decided to wear the clothes of a toddler, and didn't even have a training bra on. Joan ordered the food, paid for it all before she promptly looked at the floor near Amy she was confused as there looked like a bunch of shoe/sock scraps. "What happened to your shoes?"
Amy felt embarrassed from her tightening shirt but what her aunt pointed out made her do a double take. "What ugh... How'd I end up with such small shoes to wear?!"
"Funny..." Spoke 44-year-old Joan "I distinctly remember getting you those shoes a few months ago."
"Well, they didn't last too long..." Thirteen-year-old Amy retorted back before asking "Say, you don't happen to have a spare phone, do you?"
Joan rolled her eyes and handed her the phone while she saw the young teen start to just become a teen. The shirt she had on acting more like a tight bra for her B-cups, and her skirt not even covering her panties anymore which had started to wedge into some of her cracks. 'Has she grown over the trip?' Pondered Joan before entering along with her.
Amy nodded back and made a quick sprint to the bra section, looking for a bra her size before her clothing situation ends up getting worse and within a minute or two...
*rrrrriiiiiiiIIP!!!*
Amy underwent a growth spurt as her body got into her mid sweet 16. Her swelling tits snapping her shirt which finally gave up its losing battle. The teen blushed a bit not expecting the tit show, and sprinted to the changing room, freaking out from having to do the rest of her shopping in her new undies. Thus, she is urged to text Joan from inside, hoping her sister-in-law could get her out of this pickle.