When COVID hit, Erika Lewis was at a crossroads. The singer and new mother had relocated from New Orleans to Asheville, North Carolina, the year before, and between the birth of her son and the move, Lewis had put off dealing with a looming health problem: a thyroid tumor. “I’d been aware of it for five years by that point,” she recalled. “I was at the point where I just couldn’t ignore it anymore.”

Since arriving in Ne...