Taking the very good advice of my commentors--especially Horace, Tenured Radical and Tony Grafton--I emailed my dissertation director yesterday and quite enjoyed it. Typing that chatty, cheerful, and occasionally slightly cheeky note I almost persuaded myself that its tone reflected the actual nature of our relationship. And if there's little historic truth to that particular fiction, at least it's a hopeful way of thinking about the future.
She wrote back within 12 hours, with typical brevity, but at enough length to tell me how nice it was to receive my "upbeat and grown-up" (!) message, mention one work she's now completing, and say that I should certainly let her know if there was anything I wanted her to read in the future.
So--what more could I ask for, and reasonably hope to get?