CAN IT BE? Oh my Lord I am absolutely toooooooo overwhelmed at the incredible incredible incredible news. I think I absolutely must go have some tea and cake at the Plaza and charge it please, thank you very much, to deal with this enormously surprising turn of events.

Here is the news: Eloise, that perennial 6-year-old who lives at the Plaza Hotel in Manhattan and talks in threes and never seems to end a sentence like this one, is 40 years old. Which is incredible incredible incredible. But true.

Now, that sort of arithmetic (six plus 40 still equals six) can only happen in fiction. And Eloise, of course, is the fictional little hellion who emerged in 1955 from the wicked imagination of writer-actress-dwnightclub performer Kay Thompson and the wonderfully precise pen of illustrator Hilary Knight.

In part to celebrate Eloise's 40th birthday, Knight has included images of the hyperkinetic little girl in a retrospective of his work at East Hampton's Giraffics Gallery, which specializes in illustrational art.

Ironically, there are no original drawings from the several Eloise books, "because nobody knows where they are," said Knight. But there are vintage preliminary drawings from the artist's notebooks, as well as some recently completed Eloise images in which she is forever 6.

The retrospective, which runs through Aug. 26, also includes Knight's satirical drawings of urban characters from the early 1950s, illustrations for children's books and posters for Broadway shows. There's even a watercolor drawing by his mother, who was a designer and illustrator, that probably served as the inspiration for the image of Eloise. "I don't know what it was done for, but it was in my home all the time when I was a child," said Knight the other day, as he affectionately inspected the drawing. Though he has lived for years in Manhattan and East Hampton, the artist, who was born in 1926, spent his earliest years in a house in Roslyn. The house, he recalled, had a pond, and it had his mother's drawing.

Though that little girl wears a bustle and holds a bouquet, she has the recognizably impudent look of guess-who. "I didn't realize it until after I'd done the book - how important it was for the image and the attitude," said Knight. "It's that sort of saucy look. She's absolutely self-assured."

If the saucy girl is Eloise's visual ancestor, the Plaza resident herself was born with the help of a onetime New York neighbor, who introduced Knight to Kay Thompson in 1954. "Kay was then at the final period of her nightclub act and was appearing at the Plaza," Knight recalled. His neighbor, a literary type, took Knight to the hotel to talk to Thompson about collaborating on a book, based on a character that Thompson had jokingly created for friends. "She would talk to her friends on the phone," said Knight, "and pretend she was Eloise, this little girl who lived in hotels."

Things between the artist and the writer clicked, though "it took a while to get the story line, which was all her," Knight said of Thompson.

The story, as several generations of "Eloise" fans know - the book, published by Simon and Schuster, is now in its 34th printing - concerns a rawther well-to-do little girl who lives with her nanny in the Plaza, which she views as her personal fiefdom. The text, which is "narrated" by Eloise with a combination of arch sophistication and uncontrollable childish energy, is immeasurably enhanced by Knight's drawings of Eloise prancing, sliding, marking up the walls, calling room service with a charge-it-please insouciance, playing with her turtle, and otherwise amusing herself - if not always those around her.

Eloise's hijinks were an immediate hit, Knight recalled. "Its success had a lot to do with the timing of a Life magazine article on it in November, 1955, which literally made it take off," he said. For an unknown 29-year-old, as Knight was then, the success was heady. It was also the beginning of a close collaborative relationship with Thompson (who is listed in various biographies as an octagenarian, and whom Knight describes as "very sharp to this moment"). They produced three more "Eloise" books, working in tandem.

For the 1957 "Eloise in Paris," that meant living in a "very avant-garde" Paris hotel and scouting the city, sketchbooks in hand: "Kay, she's an extraordinary woman, she's hilariously funny. We had a great time together and ate wonderful food. It was hardly work."

A couple of years later, they were together in Russia, researching the material for "Eloise in Moscow." (Another collaborative effort, "Eloise at Christmastime," had come out in 1958.)

"In Russia, they were stupefied by us," Knight recalled. The image of Thompson, sporting a vicuna coat and black fez and downing caviar with Knight by her side, was understandably more than bland, Communist Russia could absorb.

"Eloise in Moscow" is Knight's favorite of the series: "It doesn't have the same zany quality, but it's much better drawn," he said. But it's out of print, like all the books but the first.

"It's Kay's choice," said Knight, who noted that Thompson has her own, distinct take on the Eloise books. "Whether the other books are as good [as the original] is beyond the point; she thinks they're not as good."

So for now, Knight is content to bask in the retrospective, for which he has created some new Eloise objets and a 40th 1fortieth anniversary poster.

Oh my Lord, that's right. She's really 40.

Incredible incredible incredible.

The Giraffics Gallery, 79A Newtown Lane, East Hampton, is open 10:30 to 5:30 daily, except Thursday 10:30 to 12:30; call 516-329-0803.