You look up at the ceiling and there is a door that gives you access to the next floor. You open the door and a ladder falls. You climb the ladder and enter the third room.

Room #3
There is a ghost sitting in a rocking chair with burn marks all over their body, especially around their neck. They say that they will tell you how to get to the attic if you help them solve their murder.
The list of suspects includes their sister, husband, butler, and neighbor.
Information:
- They died at 2:00 pm on their birthday.
- They had a complicated relationship with their sister.
- They had a fight with their husband the night before.
- They underpaid their butler.
- They borrowed a book from their neighbor years ago and never returned it.
- Their sister and neighbor came to visit at 1:40 pm.
- Their butler made the cake that morning.
- Their husband bought them a tie as a present.
- They opened the gift at 1:00 pm and put it on.
- Their sister lit the candles at 1:50 pm.
- No one was in the room when they blew out the candles.
- Their neighbor cut the cake at 9:00 pm.
Who is the killer?