Following an awkward transition into narrative filmmaking with 2024’s fact-inspired but melodrama-leaning “In Her Place,” “ A Child of My Own ” sees Chilean director Maite Alberdi returning to documentary cinema — albeit of the same fuzzily defined, playfully genre-infused variety that scored her an Oscar nomination for “The Mole Agent.” Based on the case of a Mexican nurse incarcerated for abducting another woman’s baby from the hospital where she worked, the film devotes much of its running