For the photographers, reporters and simple gawkers who have dogged Sarah Ferguson's every move the past several weeks, Prince Andrew's gain is their loss.

Wednesday, before her engagement to Queen Elizabeth's son was announced, she was merely an about-to-be-famous 26-year-old, without defense against the hordes who telephoned her at all hours, camped out on her south London doorstep and followed her to work each morning.

Today, however, Sarah was firmly under the protective royal wing. She reportedly spent the night at Buckingham Palace, the home of her fiance' (no question of impropriety was raised). Although she went as usual this morning to the graphic arts company where she works, she was concealed in a royal limousine, accompanied by two security guards who will henceforth be her constant public companions. Would-be gawkers were kept well away behind police barricades.

But in the time-honored tradition of the British tabloid press, the less access they have to "Fergie," as they have dubbed her, the more news they will unearth about her.

The engagement was the lead story in virtually every national newspaper today, except for the staid Financial Times (which ran an article on Page 9) and the Communist Morning Star (which ignored it). But for the tabloids, for which the royals are the staple of daily diet, the announcement opened the floodgates to what will doubtless be decades of titillating examination of the minutiae of Sarah's life, every dress she wears, every word she may or may not utter.

Wrapped inside a front page emblazoned with a near life-size close-up of the royal engagement kiss, the Daily Mirror headlined a "World Exclusive" detailing Sarah's "Life With Peanuts and Mr. Rabbit." "Once upon a time," it began, "there was a little red-headed girl called Sarah Ferguson . . . " While she loved her mummy and daddy, Sarah devoted equal devotion to her stuffed bunny and live pony, both of whom are purportedly pictured in grainy photos.

The Daily Star probed the damage done to Sarah's teen-aged psyche by her parents' divorce, and The Sun outlined "The Dress Sarah Should Wear" on her wedding day. But it was left to the Daily Express to reveal "The Truth About the Bride-to-be." Recalling "the face I know so well," the editor of a magazine devoted entirely to the royal family told of the night "Fergie cried on my shoulder" after being dumped by a pre-Andrew paramour.

Here there is some new information gleaned from the Fergie-watch:

The outfit she wore to work on her first official day as a pre-princess -- checked skirt with white blouse and blue jacket -- was one she had already worn earlier this week.

As she entered her office building, she tripped over the doorstep and nearly fell, in full view of long-range camera lenses behind the barricades.

Prince Philip, the Duke of Edinburgh and Andrew's father, made his first public comment on the engagement ("splendid"), as did Andrew's sister, Princess Anne (Sarah is "lovely," Andrew is "lucky").

After she is married, it will be incorrect to call Fergie "Princess Sarah." Just as women who marry commoners traditionally take their husband's last name, the wife of a prince (unless she is already a princess in her own right) adopts the name by which he is known. Thus, Sarah's official title will be "Princess Andrew." (This custom does not apply, however, to the heir to the throne. Burke's Peerage, the self-styled authority on such matters, takes great offense when Prince Charles' wife is incorrectly referred to as "Princess Diana." According to Burke's, she is "Lady Diana, the Princess of Wales.")

Employes of Staffordshire Potteries Ltd., in the city of Stoke on Trent in central England, worked through the night to produce a collection of Andrew and Sarah commemorative coffee mugs, featuring a black-and-gold cameo of the two on a white background. On sale this morning, the mugs retail for 99 pence each (about $1.45).

In a poll conducted for the BBC television morning news, 79 percent of Britons asked said they thought Sarah was the right girl for Andrew. Only 6 percent disapproved of their engagement. Seventy-one percent said their nine-month courtship was long enough to get married, and 82 percent said the wedding should take place this summer, rather than the fall.