Something I should have done years ago - catalogued Aisha's book collection on the internet to stop people (well, one person) buying her duplicate books.
I've made an account on Librarything and just started entering a couple of her books. I got to 98 and stopped. I'm easily going to pass 200 and have to give them $25.
http://www.librarything.com/catalog/AishaS
It's probably going to take the best part of the weekend to enter all of them, especially as she has so many books that are now well below her as well as the ones at her current reading level. Her books are taking over the house, slowly ... silently ... indidiously ... a creeping growth of books, mysteriously multiplying whenever I'm not looking.