FORT WORTH — Wendy Davis has made her personal story of struggle and success a centerpiece of her campaign to become the first Democrat elected governor of Texas in almost a quarter-century. While her state Senate filibuster last year captured national attention, it is her biography — a divorced teenage mother living in a trailer who earned her way to Harvard and political achievement — that her team is using to attract voters and boost fundraising. The basic elements of the narrative are true, but the full story of Davis’ life is more complicated, as often happens when public figures...