Not much is known about Larry Johnson sister, she is pressumed dead larr In The Bologna Incident, Larry Johnson was revealed to have a deceased baby sister that was stillborn. She is presummed dead we do not know anything about this unknown character, Upon searching larrys stillborn sister you find a picture of Lisas mum
The stillborn sister is also mentioned in the sally face art, lore and more and was most likely supposed to be born 1982, based off the information in the book.