This is how Horace Rumpole referred to his wife (she called him 'Rumpole'); John Mortimer took the title from H. Rider Haggard's She, serialized in The Graphic magazine from 1886 to 1887 and then published as a novel in various revisions up to 1896. With over 83 million copies sold in 44 different languages it is one of the best-selling books of all time.
[*By the way, why was Rider Haggard?]
I have a copy of the 1888 New Edition. I do not know how I came by it, but I must have been quite young because I remember being very impressed by some of Maurice Greiffen's 32 illustrations; Ayesha, as She was known to her friends, was a great unveiler and the pictures were mostly Victorian soft porn.
It was pretty good value for 3s 6p, with 277 closely printed pages, some featuring translations of the inscription on a fictional Sherd of Amenartas into Greek, both uncial and cursive, mediaeval black-letter Latin and black-letter English, as well as the thirty-two illustrations. It's a great story, and you can download the whole text from Project Gutenberg here, sadly without the illustrations but with the translations; some modern readers may want to skip these.
It has a tremendously plotty and complicated plot with some splendid passages: my favourite describes Ayesha's sad end. She was two thousand years old, you see, but having bathed in the flames of the Fountain of Life back then her appearance has never changed.
When a young Cambridge man, Leo Vincey, arrives with a friend in the African kingdom she has been ruling, Ayesha believes him , probably mistakenly, to be the reincarnation of her prehistoric lover Kallikrates (I said it was complicated) and urges him to to bathe himself in the flames so that he can join her in eternal bliss. Understandably nervous, he is persuaded to do so only when she demonstrates that it is really fun and quite harmless by bathing again herself. This turns out to be a very bad idea, for a second flamebath reverses the effect of the first so that, like Dorian Gray, the years catch up with her.
After much unveiling, "...she stood before us as Eve might have stood before Adam, clad in nothing but her abundant locks...". The flames envelope her, discreetly arranged, and then—ah, then (I abbreviate):
"The smile vanished, and in its place there came a hard dry look.....she stepped forward to Leo's side and stretched out her hand to lay it on his shoulder... Where was its wonderful roundness and beauty? It was getting thin and angular. And her face—by Heaven!—her face was growing old before my eyes! ...She put her hand to her hair and oh, horror of horrors! it all fell to the floor".
And so it went on.... "skin turned dirty brown and yellow", "... no larger than a big monkey...", "shapeless face with the stamp of unutterable age..." The fearful spectacle is described with a wealth of detail: no wonder the whole party swooned (the Victorians were great swooners) as the poor old thing died. Their servant Job also dies, of a fit brought on by terror, but the other two shake his cold, dead hands and then, understandably a bit fed up, strike out for the Zambesi and home, which they reach eighteen months later after incredible privations and suffering.
No wonder She hasn't been out of print since it was first published. The novel—or something like it—has been filmed at least nine times; the first version was in 1899. In 1965 Hammer Horror had Ursula Andress in the role.
[* Because he couldn't Marie Corelli, of course.]