|"||She became obsessed. She stopped sleeping because it took up too much time. She started taking meth to stay awake. She figured she could sleep later. You can guess where this is going.||"|
Sorrento's Sister (name unknown) is a minor character who is mentioned in Lacero, a short story by Andy Weir, officially set in the OASIS universe.  Since OASIS's creation, Sorrento's sister became obsessed with the virtual world. Unfortunately, she died due to a meth overdose. Her death was a key factor for Nolan's hunt for Halliday's Easter Egg.
Nolan's and his sister grew up together, but due to the OASIS they became distant. His sister spent every moment of each day in the simulation. She ignored her friends and family. The only time she wasn't in the OASIS, when when the rare times she ate and slept. Sorrento's dad died early and she spent most of the money from the will on her life in the OASIS.
Once Halliday's Easter Egg Hunt was announced, Sorrento's sister became a Gunter. She stopped sleeping by using meth, in order to spend more time in the simulation. However, this later caused her demise, as she died from an overdose. After three days, her neighbours found her.
Sorrento's sister's death was the main reason that he joined the hunt. He wanted to delete all of OASIS and stop any future deaths from happening. He becomes even more absorbed with the hunt, when he finds that Halliday has a way to remove all of OASIS. This is alluding to the Big Red Button.