answer: #Person1# is looking for a stamp to post a written letter to #Person1#'s father.
documents: #Person1#: Why are you taking everything out of your bag Lily?
  #Person2#: I'm looking for a stamp. I know I've got one in here somewhere.
  #Person1#: A stamp?
  #Person2#: Yeah, I've written a letter to my father and I want to get it in the post before midday.
  #Person1#: You've written a letter? Why not just use email?
  #Person2#: Well. Some feelings are better to be written on real paper instead of being typed on a cold keyboard. Oh, here, I find it. It's stuck in my phone case.