I'd probably just point out that she should have kept her work-related and personal emails separate to begin with, but I suppose that would be too much effort for Her Majesty.
There's so easily bleed-over. If I'm discussing the latest TPS Reports with my colleague Joe and cubicle-neighbour Francis, a note that it's Sam's Birthday Bar Crawl tomorrow night can easily crop up as an aside...
If, having logged out of the corporate account (or using a different tab/interface) to use my presumably work-permitted personal email/whatever account on company time, I instead privately discuss with @JoeJoeBaby and @FrancisTheOrc the upcoming evening schedule of bacchanalian festivities I might find myself easily seaguing into "...which means I'll need those Pre-TPS Collation Forms filled in at least an hour earlier than usual, so I can run the numbers in time to get out of the door. And is there any way you can get the Slough office to commit to their fourth-quarter figures on time, for once?"
Oh dear. So much for separation of business and personal, all the best will in the world. There are coping strategies (I don't socialise with my colleagues, in real life!) but I also make a conscious effort to never mention current professional issues upon forums such as these and don't try to indocterinate my cubicle-neighbours with the finer details of setting up an obsidian farm. More than the once, at least. Twice, at a push. The third time was forgetfulness and the fourth was because they were eavesdropping on a conversation with the security guard. I think the fifth was during Sam's Birthday Bar Crawl, in the Octopus's Arms, was probably drowned out by the loud music, hence why the sixth time was whilst stumbling over to the Hydra's Heads, or maybe it was the Elephant And Other Elephant. Whichever was having the '70s Retro evening...