Although you're tempted to shrink yourself some more just to see what she does, you think you've messed around with Kristen enough, at least as this pair of panties. She's not going to put you on again like this, but once she leaves you somewhere you can turn back and have a new adventure. If she puts you back in her underwear drawer or the laundry you can turn yourself back to the regular-sized panties and just wait until she wears you again, assuming you don't mind spending the next week or two in there.
When Kristen carries you over to her underwear drawer, you think that that's what's going to happen. She puts you on top of her dresser and starts rifling through her panties, clearly checking them. Eventually you realize that she's checking to make sure they're not all shrunken too.
Then she suddenly stops, and her face becomes ashen. She pulls out, to your dismay, the original pair of silk green panties. You modeled yourself after these panties and shoved them deep inside her underwear drawer this morning, so that when she saw you she would think you were her original, normal pair. The plan worked, at least this morning, but now she's figured out that you're just a copy somehow.
Her eyes slowly move back towards you. You are in serious trouble now. Regardless of how much Kristen has figured out, she surely understands that she now possesses some sort of demon panties intent on tricking her.