I am continually surprised by the height of mine; we were out together recently and I felt odd in myself, like I was shorter than usual, and eventually traced it to the fact that she is so close to my height -- my brain couldn't figure out which side to land on, am I my normal height with a slightly shorter adult, or is this my child in which case I have clearly shrunk? She is also wearing a number of my pre-pregnancy tshirts quite successfully, but her colouring is different enough from mine I don't have that mirror-moment that you describe so well.

Regarding Pratchett, mine got about halfway through Wintersmith before stalling, although she says she's just waiting for me to catch up, which I am trying to do as time permits. I hope yours does try Vetinari, they are some of my favourites also!