"Can you sense where your sister is now?"
Renji asked Lilith, who initially did not react, but then realized that Renji was referring to the real Miyuki.
Lilith didn't know much more about Miyuki's secret than Renji did. She thought she had corrupted and revived an elf, only to later find out that she was actually the one being actively revived by someone else.
Lilith couldn't actively sense Miyuki; she didn't have that ability.
Seeing that Lilith was of no help, Renji pondered for a moment and quickly came up with a new idea.
"Follow me."
Renji, with a confused Lilith in tow, arrived at the base of the World Tree. Recalling the memory of the path to the World Tree's lower levels from Zero and Lena, Renji asked Lilith to try and see if she could also open an underground passage here.