"Their lives, and those of their precious children" means "their lives, and the lives of their precious children." It is common to talk about any text that was created in the past in the past tense, even though it continues to exist in the present: "The advice he gave was..." "What I told him last week was..." "The plot of the oldest book written in the English language was..." ...If you need a better/more grammatically-based reason, I'll have to go look it up. :)