Felicity decided to go with the more reliable option: The cabinet. Even if the risk of noise was higher, the risk of getting seen was lower, making her chances better overall. And besides, who would even think to check under the cabinet?
The girl quickly ran to it, pulling the door open. She was met with the sight of cleaning products being stored down there, alongside the expected sight of the piping under the sinks, and... A pack of diapers? Felicity was confused by that, wondering why they were there. "Does Lucy wear them...?" As she climbed in, though, she shook her head. "They're probably just leftovers from when she was younger."
Carefully navigating around the bottles and boxes, the tomboy crouched down, managing to clear enough space to fit her butt on the ground, then closed the cabinet behind her, drowning her in darkness. All she could do was listen.
Felicity heard the door swing open, then shut again, the lock going off. Without the ability to see, her other senses were improved, letting her hear the rustling of Jennifer's clothes. Felicity guessed the sound was her getting ready to use the toilet.
About two minutes went by, and there was nothing but rustling, Felicity beginning to doubt her guess. There was no sound of the lid tapping against the back of the toilet, nor the sound of Jennifer peeing. The sound of Jennifer huffing, then saying "Dammit," reached her ears, though only barely, with this being followed by more rustling.
Finally, Felicity heard the tap of the toilet lid being raised, then the sound of pee hitting the inside of a toilet bowl, disappointed at not getting to hear anything about what she could've done. But she supposed that was to be expected, since Jennifer was in here alone at first, and she didn't think Jennifer would vocalize her thoughts until she got Lucy.