If he already knows how to encrypt, pw, etc., and she's aware of that, I'm of the feeling she's just uncomfortable with him seeing her in an intimate nature now that they're not intimate.
I used to keep all my stuff on zipdisks-I liked them because you could erase and reuse or store, but since I don't know about encryption, etc., they were not a wise choice. Now everything I do is passworded and buried in folder/folder/folder-no passwords are saved anywhere but my head( which sometimes gets me confused since I have several).
One mistake I did make was linking my personal site to the 'business' one-long since unlinked-and placing a single image from an online album into a forum, which someone later pointed out to me that also had some not-for-everyone pix(which he found by right-clicking the posted photo and getting to the album). There was a "Duh!!" moment I quickly had to fix-no one wonder all those guys were so happy to see me when we met up.