THOUSANDS in Britain wish upbeat Queen Mother a happy 101st birthday

Saturday, August 4th 2001, 12:00 am

By: News On 6

LONDON (AP) _ The Queen Mother Elizabeth, her spirits undimmed by recent illness, chatted happily Saturday with many of the thousands of admirers who gathered to celebrate her 101st birthday.

Young and old, Londoners, country people and suburbanites, they lined up _ sometimes 10 deep _ along the road to the Queen Mother's Clarence House residence and overflowed along the broad Mall that leads to Buckingham Palace.

Many stood for hours to get a glimpse of the mother of Queen Elizabeth II, and she didn't disappoint them.

When she went to a central London hospital Wednesday for a blood transfusion to treat anemia, the Queen Mother had made clear she meant to be home in time for this birthday treat.

Very small and frail in a pale turquoise coat and wide-brimmed hat, she emerged from the gates of her house shortly after 11 a.m. to a roar of applause. Troops marched past for a military salute, and a scarlet-coated brass band played a chorus of ``Happy Birthday.''

Hovering staff placed a chair behind the Queen Mother, but except for one brief sit-down when she seemed to lose her balance, she ignored it.

While two plump corgi dogs wandered around her feet, she stood to talk with each of the dozen or so children who brought flowers, cards and balloons.

The Queen Mother then climbed without assistance into a golf cart festooned with birthday balloons and made a slow tour of the crowd, accepting more flowers and good wishes.

This eagerness to chat with people and the obvious pleasure she takes from each meeting are part of the famous charm that so few can resist.

The rest of the royal family soon began to gather for lunch, including 52-year-old grandson Prince Charles, also freshly out of the hospital following a fall from his horse during a polo match Friday.

Devoted fan Terry Hutt, 67, who had waited two days for his chance to talk with the Queen Mother, said every minute of the 48 hours was worth it.

``When she recognized who I was she held my hand,'' Hutt said, who never misses a chance to meet the Queen Mother. ``I told her to keep well and look after herself. ... and she said to me, `I'm feeling much better.'''

``To be honest she really looked herself, she was bubbling,'' Hutt added.

Civil servant John Dawson said the Queen Mother was ``worth her weight in gold, she really is. ... The duties she performs at her age, it's just marvelous.''

The Queen Mother has been very popular since World War II, when she was queen consort to King George VI and they forged a bond of solidarity with the beleaguered British people.

She never really retired after his death in 1952, but carried on with royal engagements during her daughter's reign, keeping up a busy schedule into her 90s.

For the Queen Mother's centenary a year ago, a crowd of many thousands gathered in the Mall to shout their greetings when she stood on the Buckingham Palace balcony.

Seventy-year-old Princess Margaret, who has suffered a series of strokes, appeared for her mother's birthday lunch Saturday in a wheelchair.

Prince William, 19, was there with his brother Prince Harry, 16. The queen came over from Buckingham Palace with Prince Philip, joining Prince Andrew and his two daughters, Princess Beatrice, 12, and Princess Eugenie, 11; Princess Anne and her husband Timothy Laurence, son Peter Phillips, 23, and daughter Zara Phillips, 20.

Princess Margaret's daughter, Lady Sarah Chatto, also arrived with her husband Daniel and their two young children.

The Queen Mother rounded off the day by attending an evening Royal Ballet performance at the Royal Opera House.

Wearing a shimmering pink gown and silver necklace, she arrived with the queen in a chauffeur-driven Daimler. A crowd of about 200 cheered and sang ``Happy Birthday.''