Sea of Glass by Jarrod R. Keith and Allen R. Rigby

In this sequel to Still Waters, Rachel Glenn is reluctant to accept her assigned role as a young widow. She becomes so involved in the new daily affairs thrust upon her that she little time to become overcome with grief. Months later she learns that she and her new baby daughter are central figures of an international drama that threatens to permanently separate them. She also learns that her late husband, Shane Grant, has led a secret life as an operative of a secret American anti-terrorist group. His friends and coworkers step in to provide the needed guidance and protection necessary to keep Rachel and her child safe. Along the way, she learns a great deal more about Shane's secret past and begins to wonder if he is really dead or simply being hidden from her by the Agency. Rachel tenaciously follows lead after lead and ultimtely gets most of her questions answered.