A top-flight roster of actors brings the story of “Glint” to life. Emily O’Brien plays Francine, a young mother dealing with more than the usual challenges of raising a child on her own. Ava Castro plays Cecilia, a precocious young girl who bears the burden of her mother’s increasingly erratic behavior. James Edwards plays Josh, who gets more than he bargained for during a date with Francine. And James Bartz plays an unsympathetic physician who dismisses Francine’s problems.