Neither is the case here. The two are the only humans in the home and the mother's bedroom adjacent to the nursery is locked so no one else may come in. The furnishings are the crib, the potty, a bookcase and the xylophone. Only the xylophone could make noise, but only with the toddler using it, not while she's in her crib. This last time her waking seemed to coincide with her mother entering the room; I wasn't observant enough on the other occasions to notice if that were true then also.
Edited to add: She definitely just did it again the next night. This time, her mother put her in the crib and walked out of the room. She got two rooms away before the little girl popped back up. It's definitely not tied to someone entering. At least this time it happened right away, so she's still sleepy and will fall back asleep quickly.
Edited again to add: And again. Mom cleaned the bathroom and popped back in to empty the potty. The girl had just laid back down and popped up as soon as her mother walked by. While not entirely unrealistic, a toddler that doesn't want to go to bed, it's not as if she or I can argue with her red energy bar.
