I agree looking at the detail, it’s hard, though I have tried - imagine every step she took once inside her home, from work it was said she went back out to post another letter - did she drop her rucksack by the front door and pick up the letter and go straight out with it - or did she take her boots off - change into her slippers - compose the letter and then change back into her boots. Her rucksack still at the front door? - I see on the back of her door she has hooks - is that where her rucksack lived? - it would be nice to have a plan of her house - in as much detail as possible.