...!

Jessica was no more. She may have taken solace in knowing her fall had saved her aunt that night, but Yharnam was doomed nonetheless.
Jessica's body was worn and owned by a large slug that hunted for the eyes on the inside of a hunter. The thing having had enough of its diet to grow to full size quickly with Jessica.
Later such beasts would be called brain-suckers, though few knew the actual process by which they were grown. Her first encounter having placed its seed in a much more lasting way than the others. But there are worse ways to go.

She was found and restrained by church hunters soon after. And the choir is always looking for more test subjects.