Tammy was a successful attorney until she decided to retire from active practice (for her health, as she says now). Since her retirement, she has concentrated more on her family, which she had little time for when she was focused on her career. She is trying, very quietly, to rebuild some bridges.
She recently learned that her real father was Jacob Everett, the famous (and reportedly deceased) novelist, and she decided to take his last name as her own. She has read all of his novels, and many of the protagonists (most commonly described as macho, taciturn, grim, stoic, reserved, individualistic and humorless) appealed to her, though of course they were all male.
When she and SarahBeth have been together, Tammy has been appalled at the younger woman's relentless broadcasting of her urges, opinions, humors, desires and bodily functions to the world, but they do share one thing, which is a disdain for what SarahBeth inevitably refers to as "mushiness." The Old Man (as Jacob Everett was known for most of his life) would have agreed with that.
She does not appear in U-town. In the new novel, she first appears in the chapter Return to U-town.