I would imagine they were interested in her simply because she was the last child/teen known to be playing with E....the 6 year old would have said Elizabeth and AB were playing in the woods and sent me home, or something similar. Given her probably easily accessible background...plus whatever "talk" floats around the community, I would imagine gravitated them towards her, imo.
I could definitely see them search her room taking her diary. Just a freak thing that she would be cocky/stupid enough to write what she had done.
Still don't understand that delay tho....even if they read that E was dead, there's always the chance that AB hadn't finished the job, or that an animal/the elements would destroy evidence around her body.
I'm thinking they didn't get around to the diary until Friday.
sigh.