might have been a plane side check in as there was no more room in the overheads about 2/3 through boarding. Honestly/luckily i was half asleep through most of it, but i was awake to hear her say she's on the wrong flight and remember hearing the captain say they were looking for her bag. I see the lax/sfo flight was delayed an hour too, maybe her checked bag was on that plane and when she didn't board they delayed that to remove it?