How to quote a draft in my thesis? For my bachelor thesis I needed a certain source. As it wasn't accessible neither on the net, nor in my library, I decided to ask the author directly. She was kind enough to send me a draft of the text in question, explicitly allowing me to use it for private academic purpose. 

Now I'm in the middle of my thesis. How do I cite a draft that doesn't even have a date? If I had the published version, I'd simply cross-reference, but I don't, and adding the page number of a word document that my supervisor doesn't have seems utterly useless. Do I simply leave out the page number (it's a very short paper), or do I add the paper as an attachment? 

I know this is something I'd normally ask my supervisor. Unfortunately, communication with her is not something I'm interested in, for personal reasons. I'm therefore looking for a reasonable advice that has nothing to do with her preferences.
If it has been published, ask the author for a pdf of the published version (from your question I got the feeling that the paper has been published). This would also be easier to share with your supervisor later on. It makes no sense to cite or quote a draft version if the paper has been published. At least ask if the draft has identical content as the published version. If so, you could maybe get away with using the draft but citing the published version in your reference list (not ideal though).

Otherwise, cite it as a working paper/draft, by including author, title, and the date when you recieved the paper, see e.g. Chicago manual of style online or MLA style guide.