flash
She was walking towards the front of the room when she felt it in her chest. She hadn't made a wish and her breasts were swelling, just this time her clothes were not changing to match. At the same time, she could feel her panties starting to twist and shift, changing somehow.
Jules reached the front of the room and turned around. Everyone was staring at her chest. She could feel her bra biting into her back and her breasts swelling, swelling to fill all the available volume in her top.
Everyone was staring. That meant whoever was making wishes wanted people to know. Jules's eyes found Karyn who looked back in fear and confusion. She must be realizing what was happening too.
Her chest swelled again and a button on her red blouse blew. There was now a gap where her students were getting a front-row peek at what was under her blouse. She had to get out of here. She turned and strutted towards the storage room, the room where she arrived in this body. She stumbled as her underwear reformed, sliding up and between the cheeks of her ass.
“C-class, I just need a moment, continue reading please.” She stammered out. The class laughed. Her breasts continued to swell and her g-string finally settled, the new fabric quickly soaking up her arousal. Her previous b cups had to be upper c cups by now.
Hyperventilating she grabbed the door to the storage room and shut it behind her, her bra-snapped and in the process released all the pressure on the shirt, instantly shredding the front of it.
“I wish no one thought that was strange.” She said and immediately regretted the words. Fuck.
flash
"I wish no one thought it was that funny." Fuck. She had to stop making wishes.
flash
"I wish no one noticed my breasts growing."
no flash.
"I wish I knew why it didn't work."
You already wished that no one would find it strange or funny. It's not strange because your classroom has a curse that any female teacher's breasts will grow and it's not funny because it usually causes severe emotional distress especially since only the people who witnessed it can remember the old reality. The rest of the staff have yet to realize the problem. Your wish can't contradict a previous one.
Jules was pretty sure that wasn't how the stone/necklace was supposed to work but she really had no choice. It was too late. She had already confirmed this reality. This shitty stone. Well, necklace now. She sighed, her breasts finally stopped growing. Somehow she knew they were low D cup now. She turned to the mirror not particularly excited to see her latest folly.