The experience of being a pair of Kristen's panties is so wonderful that you're not giving it up anytime soon. You may be stuck in the hamper, but that doesn't mean you have to give up. Sure, the best part of being Kristen's panties is being worn, but this way you'll get the full experience: a few days in the hamper, then going through the washer and dryer and then back into her panty drawer. You've loved this experience so much so far that you could really see yourself staying as Kristen's green silk panties for a long time.
And you don't even have to be that patient. Now that Kristen's in the shower, you can turn back into a person, go back into her panty drawer, and once again try to pick out the pair she'll wear and turn into those panties. Just like you did yesterday. It worked then, why can't it work now?