Terri Blackstock used to write for Harlequin and Silhouette (which both churn out romance novels) before she had a "spiritual awakening" and realized that "she was not using her gift as God intended. It was at that point that she she recommitted her life to Christ, gave up her secular career, and made the decision to write only books that would point her readers to Him." (from "About the Author")
You have to admire that. Dawn's Light is book #4 in the "Restoration Series" - an ambitious undertaking where the author follows a Christian family during a global catastrophe that sweeps the planet to the days before electricity. The inconsistencies and impossibilities in the story may be increased by only having read the last book of the series.
The Branning's struggles are immense and Blackstock does a good job of illustrating the importance of a Christian witness and the struggles within each believer's heart. There is nothing theologically problematic in this novel.
However, Blackstock writes at an exaggerated emotional pitch (which is understandable considering her writing background) that reminds the reader of spending time with a hormonal fifteen year old where not much happens but much time is spent in tears, sighs and rehashing of emotional dramas. The day may end with satisfaction, but it's a bit exhausting along the way.