On the opening & ending. In the opening, she is alone, it's shot from the front and there's an extended period where she covers her eyes and moves down to covering her mouth. There's moments where she directly looks into the camera too. I've seen some people interpret this similarly to a dream sequence/metaphor where it represents her mental state. like trying to forget what she's seen and keeping herself from screaming kind of thing. In the ending, it is shot from her side and she is joining a group of others (mostly elderly women? it looks like). This was easier to understand because of the acupuncture right before it and the couple times she mentioned doing this to "forget the bad memories" earlier. I'm not sure if the other women mean anything. Maybe they're all mothers and all have their own stories. There's a man in the line too so maybe this is all coincidence and doesn't mean anything. ANYWAY i think "thinking too much into it" like you said is fine since good directors shoot their films purposefully and there's definitely evidence that holds up in great movies that certain aspects were intentional. Maybe not every little thing but it's not all pointless overanalyzing like some people might say.