Okay, this story is from someone who presents as a theist - so my BS radar is mounted and activated
Never forget the dental miracles! And the insights they gave us.
Sure, it might not be statistically impossible but I'm more inclined towards the more likely probability of this being another fabricated "me too" miracle.
1) Who stores children's old essays in their bible?
2) When I was a Scout and at school ALL my essays were returned to me after marking.
3) Who would wait 2 months after noticing an "old letter" stuck in a second hand book before reading it?!?!?! FFS
4) There is even some lamenting about lost opportunities to further embellish the story - like there might be some kind of more meaningful message if only she remembered which chapter of the bible the old essay was inserted into. (Or that may be a follow-up opportunity securely in the bank for more attention seeking at a later date.)
It simply doesn't add up, but rather smacks of making it up
as she goes along - a skill theists do happen to get a lot of practice at