Finding Audrey by Sophie Kinsella (preloved/used/secondhand novel)

Audrey can't leave the house. she can't even take off her dark glasses inside the house.

Then her brother's friend Linus stumbles into her life. With his friendly, orange-slice smile and his funny notes, he starts to entice Audrey out again - well, Starbucks is a start. And with Linus at her side, Audrey feels like she can do the things she'd thought were too scary. Suddenly, finding her way back to the real world seems achievable.