His Other Wife by Deborah Bedford

Since her divorce from Eric, Hilary has done everything she can to control life for herself and her son. Beneath a calm surface, she is terrified of failing Seth. She’s worked hard to raise him on her own, and she’s succeeded – he’s now set to graduate from high school and enroll at the University of Illinois with a full scholarship.

But Hilary’s worst fears are realized when there is a rock-climbing accident at a post-graduation campout. A young girl is hurt, and Seth is arrested. Pamela, Eric’s new wife and Seth’s stepmother, blames Hilary for letting Scott go to the campout in the first place. With Seth’s college scholarship now just a distant memory and his entire future at stake, the two women must come together for Seth’s sake.