Time for no diapers?

So, 6 years into parenthood has given me 6 years of nonstop diapering experience, not to mention babysitting before parenthood. Now, my littlest is deciding she'd like to be like big sis and big bro. I have often gone in search of her when I suddenly don't hear her anymore--a tale tale sign of her either being extremely adorable or making mischief. Lately when I go on these searches I often have found her taking off her diaper and getting up onto the toilet. Yes, I believe I've mentioned she is an assertive girl and that goes for potty-training herself as well. She has quite the way of getting up onto the potty, with or without a stool and likes to do it herself. She's: been successful in going several times, has peed right in front of the toilet after taking off her diaper while just staring into the toilet with fascination and has also peed on the step stool while washing hands right after an unsuccessful toilet time. The other day tops all. I realize she's been quiet for several minutes and go in search wondering what she's up to. I hear nothing and head upstairs. Still nothing. Then I hear some tiny noises coming from big sisters' room. I open the door to find her sitting on the floor with her pants and diaper next to her trying desperately to put on B's underpants that she got out of the drawer. I laughed hysterically before getting her put back together and suggested we get some for her next time at the store. She gave a very enthusiastic, "YEH!" (Secretly I hope she holds off until after our next few moves in the next 6 months. But, try telling her that would likely land me one of her adorable scowls of disapproval.)