What event made lily believe even stronger that her mother may have been in the pink house

Lily escapes her thoughts by going into the pink house for a drink. She finds May making trails of graham crackers and marshmallows to lead bugs out of the house. Lily recalls that T. Ray had mentioned that Lily’s mother used to do the same thing. Lily asks May if she remembers a Deborah Fontanel, and May says yes, Deborah stayed out in the honey house for a while. Lily feels light-headed and goes out to the honey house. Lily becomes obsessed with the idea that her mother walked in the very same room in which she stood. Lily eventually falls asleep.