A mystery story that completely baffles me

I am completely puzzled by the Elizabeth Strout story (Strout is a fine writer of course, though I'm not persuaded that she knows much about Providence) - At Trinity Repertory Company, or some such title - in the Providence Noir (Akashic) collection (Ann Hood, ed.): about a production of A Doll's House at Trinity Rep in what seems to be maybe the 1960s or so? - certainly before the so-called Providence Renaissance and set in an era when a theater production would be a big deal in Providence, meriting extensive coverage in the press (i.e., the Journal). In this production an ingenue plays the lead, and the story is narrated by the owner of the boarding house (today, as she notes, she would call it a B&B) where the actress and her still-young mom are staying during the run of the show. We don't learn too much about either of them - it's a pretty tight story - but we learn in the first paragraph or so that the actress met a tragic fate during a performance. At the end - I'm really not giving anything a way here but stop here if you wish - we see her fall dead on the stage in the last act. (I'd wondered whether her death involved a shooting w/ a live gun that was supposed to be a prop - but I guess that would have to be in Hedda Gabler.) The narrator tells us that the police investigated the death for some time, came around to the boarding house asking questions, but found nothing suspicious. Then - and here I will "give away" the ending although I could make no sense of it - the narrator reports that the mother left behind a scrapbook (unlikely) and she looked through it and found something of interest. What?: "the sun," and with that the story closes. Huh? Was this a misprint? Was it a play off the word "noir"? Is it suggesting that the young girl was secretly unhappy? Secretly happy? Did I miss somethign? Anyone with a theory, please weigh in via the comments box below.