"...let her think this took a lot longer to decide. That might help us later on"
I loved this, because, as a parent, I have done the same thing once or twice.
This is a nice story. As you mentioned in your notes, Hermione and Harry are both OOC, but they are not radically so (after all its not like either of them is shaking up with Snape or Draco - shudder) and its AU. There were a few minor punctuation errors and a couple places where you put in the wrong pronoun, but all in all it was well written.