Sounds from the prosecution the other day, the 257 cover much of her career - i.e. not nearly every hand over from the year June 2015 - June 2016, only some are from then.
I see mention today of her diary recording her moving home, if you just shove important docs that need secure disposal (which you don't at the time have a shredder for or don't get round to doing) to one side, then like me, you probably move house and have a box of documents, or a bigger moving box containing assorted stuff that you know can't simply be thrown out (thus labelled "Keep") and needs going through at some point. I'd guess the 31 are just the ones since the last time she emptied her bag out and dealt with them. And I'd guess the 17 don't relate to 17 babies, but 17 shifts where she was caring for most likely the last few babies.
Like others, I'm struggling to picture this bag - how are the handover sheets concealed within it?