Yes

The change in Melanie's demeanor is apparent almost immediately. Before the sound of John's snap had even faded into memory, Melanie dropped both her arms from her chest and stood there as if...well, as if standing there topless were the most normal thing for her in the world.

"Ookaay," John said, drawing the word out a little out of caution, "How about a quick couple of questions to see if the change in personality took hold?"

"M'kay," Melanie shrugged.

"How do you feel now about showing up to breakfast in what you're wearing?"

"Well," Melanie looked down at herself, "I think I should fix my top first."

"What do you…?" But before John can finish, Melanie pulls the remains of her top out from her underboob, and pushed it down past her hips where she promptly let it fall to the floor. She turned her head back to John with a neutral expression on her face as she deftly stepped out of her top and kicked it at her big sis.

"So, you have no problem showing mom and dad your new tits?" John asked, catching the top in midair and then setting it on the counter.

"Why?" Melanie asked, genuinely confused, "They're just tits. Every gal's got 'em."

"Don't you remember being embarrassed about them not even a minute ago?"

Melanie rolled her eyes up and to the left, thinking, "Yeah. That was pretty stupid. Then I asked you to make me like this."

John nodded, "Alright, so you don't have any hang-ups about walking around in public like this?"

"Nope," Melanie agreed.

"Or going to school?"

"Dress code, remember? But yeah, no prob, Bob."

"To the club?"

"Pfft. As if the bouncer would even let me in."

"At night, in a dark alleyway?"

"Fuck, no! That sounds like a good way to myself ****!"

"So it changed your opinions on toplessness, but not your common sense or powers of self-preservation," John thought out loud.

"Well, that's good!" Melanie grinned, "I guess whoever gave you this power is smarter than you are!"

"Hey!" John protested.

"Let's go get breakfast, I'm starving!" Melanie rushed out the door before John could stop her. John looked at herself in the mirror, sighed, and snapped her fingers. There, her teeth were brushed, and good thing too: she had to hurry if she were to salvage the dumpster fire that was no doubt about to happen down in the dining room when Melanie showed up topless and with a massive change to her bust.