Start with high-confidence parenting grown kids books, then narrow by subgenre or adjacent topics.
Coping With Your Difficult Older Parent
Grace Lebow, Barbara Kane
The Parent's Guide to Helping Teenagers in Crisis
Rich Van Pelt, Jim Hancock
Our Mothers, Ourselves
Henry Cloud, John Townsend
Raising Passionate Jesus Followers
Phil Comer, Diane Comer
Praying the Scriptures for Your Adult Children
Jodie Berndt, Jim Daly
Doing Life With Your Adult Children
Jim Burns Ph.D, Jim Burns
Trapped in T Mirror
Elan Golomb, PhD
The Power of Praying for Your Adult Children
Stormie Omartian
When Our Grown Kids Disappoint US
Jane Adams
A Light in the Dark
Kenneth M. Adams, Mary E. Meyer
Beautiful Boy (tie-in)
David Sheff
Adult Children of Emotionally Immature Parents
Lindsay C. Gibson
Adult Daughters of Narcissistic Mothers
Stephanie M. Kriesberg PsyD, Wendy T. Behary LCSW
Children of the Self-absorbed
Nina W Brown EdD LPC, Nina W. Brown