For many years, Lisa Bertini, 46, practiced employment law as a dutiful hired gun for corporations. Tall and slender, her dark, determined eyes offset by a head full of curly blond hair, she’d stride into court on behalf of Xerox or Food Lion. But three years ago, she started her own law firm in Norfolk, now called Bertini Law, and carved a more treacherous path. About 80 percent of the time, Bertini is a plaintiff’s lawyer. In Virginia, that means the law isn’t necessarily on her side.