You can use NoveList ( a database available at most public libraries) to search for titles. Also, use Worldcat. I used the subject headings: Brothers and Sisters, Death, Bereavement
Here are a few from the past 5 years:
Dessert first (Sep 2016)
By: Gloster, Dean M.
High school sophomore Kat struggles with her twelve-year-old brother's recurring leukemia and likely death while coping with mean girls at school and possible romance.
Popularity: 1 Stars Fiction Teen
Possessing Jessie (Mar 2010)
By: Springer, Nancy
High school senior Jessie, blaming herself for her selfish, manipulative brother Jason's death, tries to comfort her bereft mother by dressing and talking like him, but soon his spirit is taking over her life, while Jessie's best friend Alisha desperately tries to save her.
Popularity: 2 Stars Fiction Teen
The good brother (Jun 2015)
By: Chen, Elaine
Away from the influence of her parents and comparisons to her dead, overachieving brother, Tori Wong's attempt to start over is complicated by a trio of spirits from her past who arrive during the Festival of Hungry Ghosts.
Popularity: 1 Stars Fiction Teen
The summer of letting go (Mar 2014)
By: Polisner, Gae
Four years after her brother, Simon, drowned while in her charge, Francesca, now fifteen, begins to move on after a summer caring for Frankie, who seems to be Simon reincarnated, and getting closer to her best friend's boyfriend.
Popularity: 2 Stars Fiction Teen
The vanishing game (Feb 2012)
By: Myers, Kate Kae
Seventeen-year-old Jocelyn follows clues apparently from her dead twin, Jack, in and around Seale House, the terrifying foster home where they once lived, and with help from childhood friend Noah she begins to uncover the truth about Jack's death and the company that employed him and Noah.
Popularity: 3 Stars Fiction Teen
Thicker than water (Jan 2016)
By: Fiore, Kelly
Arrested for dealing drugs and playing a part in her brother's death, CeCe reflects on the injury that led to her brother's drug addiction and her fateful decision to steal and sell his drugs to protect him and save money.
Popularity: 2 Stars Fiction Teen
What happened to Ivy (Sep 2012)
By: Stinson, Kathy
When David's severely disabled younger sister drowns while in the care of their father, he suspects that her death might not have been an accident and must confront his own feelings of guilt while struggling with moral questions about what is right, what is merciful, and what can be forgiven.
Popularity: 1 Stars Fiction Teen