"As a matter of fact, dearest Jamie, we should get Karyn to come!" Sarah chirped.
"Don't! Please!" Jon pleaded.
"Hush it, tubby! I wish Karyn was here and unable to try and take the stone from me." Sarah wished.
"Jamie? What the...? Sarah, dammit! what have you done?" Karyn barked after she materialized. "Give me the stone, now!"
"Tsk, tsk, Karyn. Aren't we a tad bit pushy?" said Sarah. "Now let's see... I've punished Miss Jamie for her formerly male-self's intrusion on my privacy, and it was a blast, so now I'm going to play a couple tricks on you for letting your pervert boyfriend spy on me.
"I wish that Karyn was compelled to tease Jamie mercilessly about her new appearance, which cause Jamie to binge eat occasionally, insuring that she will either maintain or... improve her pudgy figure. Also, I wish that despite the teasing, the two of them found each other irrestible both as friends and sometime lovers." Sarah paused for a moment, pacing around the trembling duo.
"Don't do this, you... you... evil bitch!" Karyn spat.
"Karyn! I'm appalled! You seem so prim and proper! Maybe I'll have to fix that sharp tongue of yours," Sarah sidled over to Karyn's side. "I think I'll have a little bit more fun with you..."