OK, I looked and I had loaned out The Hangman's Daughter a few weeks ago. It's been returned, but I no longer have the option to lend it.
None of my popular books is available for lending. I have one nonfiction book and one religious book I can lend. Lendability is determined by the publisher and it seems most mainstream publishers do not allow it. My Janet Evanovich, John Sandford, Kristin Hannah... none of those are lendable. It doesn't seem to be related to when the book was published either. I have some of Evanovich's first books and they're not available to lend.
However, if anyone wants to read about the Warren Jeffs saga or read Left Behind on Kindle, those are the two books I have available.