Thus her appearance last week in the French Indoor Open in Paris, which also marked the return of Steffi Graf after three months out injured, had the trappings of a state occasion. Queen Mary was back among her adopted subjects.
In a room set aside for press conferences, deep in the bowels of the Stade Coubertin on the south-western outskirts of the city, Pierce sat doing a doodle of a tennis racket, a sure sign, one might think, of the depth of her relationship with the sport.
But were there ever times when she felt less than totally committed to it? "I love tennis 100 per cent," she said in the airy Florida drawl that not many French women speak English in. "But everybody has their moments when they're a little bit tired, stressed out, and need a break."
Pierce, of course, knows all about that. She remains, in Britain at any rate, as famous for missing last year's Wimbledon as for anything she has achieved on the court - finishing runner-up to Arantxa Sanchez Vicario in the 1994 French Open final, for example, or beating her in the Melbourne final last month.
Faced with the prospect of her notorious father, Jim Pierce, turning up, and the media feeding frenzy that would surely follow, Pierce decided that she and Wimbledon was one doubles partnership that could wait. And with that decision, Pierce added another chapter to the growing legend of the girl born in Canada and brought up in Florida, where her American father gave her the harshest of tennis educations before he was banished from her life and she and her French mother branched off on their own. And all this before she was out of her teens.
Pierce, just 20, leads a little more settled existence now. She lives for nine months a year in Florida with her mother and 18-year-old brother, David, who is a student. She would like to have gone to college herself, she said, and become a paediatrician. She referred to the Nick Bollettieri Academy, where she is coached by a Dutchman, Sven Groenveld, as her family, although Mrs Pierce remains the rock of constancy in her daughter's life, accompanying her to all her tournaments while exuding an air of both pride and protectiveness.
It is still not easy being Mary Pierce, whose combination of glamour, talent and vivid personal history have made her an object of fascination throughout tennis. That much is obvious from both the exaggerated way she responds to errors in her tennis to the acute wariness she displays in dealing with the press - or at least the British press. To ask her too many questions about her father was to risk having the rally cut short.
Before that happened, she did offer one or two insights. Her father's coaching was brutal to the point of physical violence, but did Pierce still feel any residual benefit from it? Or was it all too far in the past? "Not at all," she said. "I worked with my dad for eight years, and it was like 15 years with anyone else. So I don't reckon it was so bad."
Would she recommend this sort of regime for other youngsters? "To a certain extent, yes. If it were the coach, then fine, but if it's . . . I mean you shouldn't be so nice but you shouldn't be so mean, either. There's a happy medium where you have to know when to push the girl or boy and when not to."
As for this year's Wimbledon (all she would say of last year was that "some things came up"), Pierce is definitely planning on being there. "I'm really looking forward to it, and I don't see there'll be any problems."
For the moment, Pierce has other territories to conquer - France itself, for example, which was why last week's tournament, her first "at home" since becoming a Grand Slam champion, was so important. There was something of the charm offensive about it as she "did her big day with the media" as her Women's Tennis Association minder put it, and took the opportunity to launch the Mary Pierce Fan Club.
The MPFC stand, on the concourse that circled the centre court, was a study in image projection, featuring Pierce in a series of striking poses against the backdrop of the sea - leaping balletically across the sand as gulls whirled overhead, sun- worshipping on deck, strumming a guitar below. The message was, this girl's got soul as well as body.
"I think the French are starting to get to know me," Pierce said in a way that seemed to acknowledge that this was not a straightforward process. One suspects this has less to do with whether someone who is abroad so much and whose first language is English can be described as "really French" than the sharp edges to her personality.
Her first-round match, against Rennae Stubbs of Australia, conveyed a lot. In coming through to win from 5-1 down in the third set, Pierce showed what extraordinary determination she has to back her powerful hitting. But when it was all falling apart in the middle of the match, we saw her other side: the haughtiness and the flouncing about which, even if it is Pierce's idea of what constitutes French sophistication is not one shared by most of her new compatriots.
She does seem to rub people up the wrong way. There was the rather cruel moment during the Australian Open when Natalia Zvereva, a much jokier and more easy-going character, mimicked her drama-queen opponent from across the net, an incident Pierce claimed not to have seen. "If it amuses the public and she's having fun, I don't mind," she said, somewhat unconvincingly.
Then Pierce got into trouble with Stubbs, who accused her of trying to put her off on her second serve by jumping about on the baseline. "For the No3 in the world to resort to those tactics is pretty disgraceful," Stubbs said.
There is a more sympathetic side to Pierce, but not many people get to see it. One who has is the former French star of the Sixties and Seventies Pierre Barthes, who now runs a tennis school in the Midi. During the lowest point in Pierce's career, two years ago, when her father was having fights with her bodyguards, it was to Barthes that she turned, all her vulnerability exposed, telling him, "I don't know how to play", and that "when I win, I don't know why, and when I lose I don't know why either."
Barthes said he asked Pierce why she had gone to him for advice, and her reply was: "Because I trust you." He did help her for a couple of months, enough time to discover that she "was a great girl, charming and nice", and also to arrive at a theory about her manner on court.
"She has had a lot of critics," Barthes said, "people who saw her as insupportable, difficult. I am sure it all goes back to the education she got from her father. If she did not win she was always having to make excuses. We still see that now, but it is getting better. I remember when she was playing at my club one day and she was being, shall we say, not very modest, and I told her, `Mary, this is not right,' and of course she knew it and at the end of the game she was saying `I'm sorry, I'm sorry, I shouldn't behave like that.' "
All sports people suffer in their pursuit of success, Mary Pierce more than most. As she advances on the high ground of women's tennis, the challenge is to realise that she doesn't have to be like that.Reuse content