Start with high-confidence ya blended family stories books, then narrow by subgenre or adjacent topics.
The Princess Diaries, Volume II: Princess in the Spotlight
Meg Cabot
Getting the Boot
Peggy Guthart Strauss
Things Hoped for
Andrew Clements
Camilla
Ann Marie Lee, Madeleine L'Engle
And Both Were Young
Madeleine L'Engle, Léna Roy
The Ruby Notebook
Laura Resau
Happy Families
Tanita S. Davis
A Bridge to the Stars
Henning Mankell
Me, Penelope
Lisa Jahn-Clough
The Other Side of Blue
Valerie O. Patterson
Wonderful Feels Like This
Sara Lövestam
The Crying Heart Tattoo
David Lozell Martin
If Only
Richard Paul Evans
Guitar Notes
Mary Amato
Last Chance Joey
Meredith Resce
Things to See in Arizona
Mary Vensel White
