She uses Time Machine. I had backed up her laptop to Time Machine (for a different reason) over the weekend, but the slideshow does not appear on the Time Machine. (Further explanation: I was migrating her account to a new Macbook, and got everything over to the new computer, but noticed that her slideshow did not show up in iPhoto on the new machine. That should have been a clue that something wasn't right, I guess.)
She had not exported out of iPhoto. It was still inside. I've seen something about using the + button at the LL to create slideshows to save -- I don't know if she did it that way or not.
Should have been more clear. The slideshow was lost just an hour ago. She is still working on the older Mac.
Saturday: Slideshow started on older Mac
Sunday: Did a Time Machine backup, then created duplicate account in Newer Mac (my own laptop) from the backup. The slideshow did not show up when I looked in iPhoto. Everything else looked good. My wife continued to work on her older Mac.
Today: Accidentally deleted the slideshow.
I will try that when I get home. Time Machine is on an external hard drive, so I'll have to hook that up, but I assume everything else above is the same. I don't understand why I should be able to restore from Time Machine, but it still didn't appear when the account was ported to my laptop (Snow Leopard.) Still, worth trying. Tnx.