12 for 2012: No 10 Francesca Halsall, swimmer

Our monthly series presenting potential medal-winners at the London Games in six years' time turns to a jewel of the pool - and hears how her mentor prepared for the greatest show on earth

At the BBC's Sports Review Of The Year show last December Francesca Halsall got to meet Theo Walcott. "Yeah, it's great," she says. "I can tell everyone, 'I've met him'."

And vice versa. Theo Walcott, the joint runner-up in the 2005 BBC Young Sports Personality of the Year award who was not required to get his toes wet at one of this summer's major sporting championships, can tell everyone in the Arsenal dressing-room and beyond that he has met the joint runner-up in the 2005 Young Sports Personality award, who had to plunge into the deep end for her country at the European Swimming Championships at Budapest in August.

Actually, Halsall had already done more than dip her toes into the water of senior international championship competition before she got to the Alfred Hajos Pool in the Hungarian capital. As the 15-year-old baby of the England swim team, she won two relay silver medals at the Commonwealth Games in Melbourne in March.

Still, it was something akin to being asked to take the deciding penalty in a World Cup final shoot-out when the schoolgirl from Southport stepped on to her blocks, ready for the last leg of the 4 x 100m medley relay final on the last day of the European Championships. Terri Dunning, Great Britain's third- leg swimmer, was a body-length clear in the gold medal position.

Britain had never won the event before, but on the final leg for Germany was Britta Steffen, the emerging new wonder woman of the water who had shattered Libby Lenton's world record in the final of the 100m freestyle. No pressure there then for Miss Halsall, just four months past her 16th birthday and two months past her GCSEs.

"I was standing on the blocks and my knees were shaking," she reflects, sitting in the meeting room at the Everton Park Sports Centre waiting for her evening session in the pool. "I was thinking, 'This is going to be so much hard work'.

"I did my changeover. I was like, 'Right, I'm off'. And I was thinking, 'Come on Fran. Don't make your stroke rate go too high. Don't try and go too quick.' And I'm like, 'Oh no, I am going too quick. She hasn't caught me up yet'. Because before the race I knew she had amazing turns, the best turns a female's got in the entire world. So I was like, 'She's going to come off the turn after me. I've got to get into this turn as fast as possible'. And, looking back at it, it was the fastest turn in my life.

"With 15 metres to go I was breathing to the side where she was and I saw her and I started to panic. My arms felt like they were starting to come in behind my ears. And I touched [the wall]. And she touched at the same time and I was like, 'Oh no. Oh no'. And then I looked up at the scoreboard and I just saw the rest of the British girls going mad. It was fabulous. It was like the best feeling ever."

It had every right to be. The 16-year-old had held off Steffen - the great Britta - by a margin of 0.11sec. She had a European Championship gold medal to go with her Commonwealth silvers and her GCSEs.

This year has been a vintage one for British swimming, with a swag of 36 medals (15 of them gold) from the Commonwealth Games and a record haul of 13 medals (two of them gold) from the European Championships. Of all the achievements, though, it has been the sparkling form of Halsall that has pointed towards a golden future in which Britannia might well rule at least some of the global swimming waves.

Fourth in the Commonwealth Games and fourth in the European Championships as a 100m freestyler, the girl from the lower sixth at St Mary's College in Crosby stands 16th in the world rankings in the 100m free (with 54.88sec) and 15th in the 50 free (with 25.28sec). The youngest of the swimmers ranked above her are her seniors by four years. In the long-haul race for gold, silver and bronze in 2012, it is fair to say that the Southport sprinter is more than promisingly placed.

It is fair to say, too, that her feet remain firmly planted on terra firma - apart from the 20 hours a week when they are ploughing through the water at the Everton Park pool, that is.

"I think it's my friends at school who keep my feet on the ground," Halsall says. "At school I'm just like every other girl who goes to the sixth form. When I came back from the Europeans, they're like, 'You only won one gold medal. Where's the other four?' I'm like, 'It's not that simple'.

"I think because I actually haven't got an Olympic gold medal around my neck I don't feel I've achieved as much as I can, so it all just flies over my head and by the wayside. I don't know... I just keep chugging away until I get what I want, like every other thing really. Like, if I want a posh dress for my prom, I'll keep asking my mum until I get it." At which point, with everyone in fits of laughter, mum gently interjects: "It might not be as simple as that with an Olympic gold medal."

Indeed not. But if Halsall does fall short of the No 1 item on her wish-list it is unlikely to be for the want of being well grounded. A highly bright and highly bubbly individual, she is a credit to her parents, Diane and Andrew, who share the duties of ferrying her to and from training twice a day. She is also a credit to Colin Stripe, the coach who guides her at the City of Liverpool Swimming Club, and who launched Stephen Parry on an international swimming career that led to Olympic bronze in the 200m butterfly in Athens two years ago.

Not since Adrian Moorhouse struck gold in the 100m breaststroke in Seoul has Britain boasted an Olympic swimming champion. That was in 1988, two years before Halsall was born.

There have only been six British gold medallists in total in Olympic competition since 1912. "Well, we've had Anita Lonsborough, who I speak to," Halsall says, knowing her history (one of her AS-level subjects) and knowing the Daily Telegraph's distinguished swimming correspondent, winner of the 200m backstroke gold in Rome in 1960. "She's a very nice woman, very inspirational. So people have done it, and I'm sure other people can.

"I was looking the other day at how many medals are on offer at the Olympics [in the women's swimming events] and there's 75. I was thinking, 'Well, if 75 people are going to get medals why can't I be one of them?'

"I think being in the position I'm in now - with all the support I get from the English Institute of Sport, from Lottery funding and from my sponsors, Kellogg's - everything's in place these days for young athletes to get where they need to be. It's just that inside them they need the drive to want to achieve it. And I think there's quite a few people, with London getting the Olympics, who will have that."

The Icon: A message from Sharron Davies

My last international competition came in 1992, but there have been few changes in swimming since I competed - you still need to put in the training, have good race preparation and, most importantly, have that special something to become a champion.

This is not something that can be given to you - it's a quality you need to have, and I believe Fran has it.

She is a very bubbly and enthusiastic character but also has a cool confidence about what she is capable of doing, which she proved at the European Championships in Budapest in the summer.

Fran had a very busy schedule but got better with every race and pushed herself up to the 200m distance, which takes a lot of work. What I would now like to see her do is learn to cope with expectation. It's a lot easier to rise to the top than stay at the top, and having risen through the junior ranks it will be interesting to see what she does on the senior stage.

I would advise that she now looks to 2008 and Beijing, where she can get the butterflies out of her stomach and experience an Olympic Games as part of a strong team. That's what I did at the age of 13, and four years later I had been there and done it, so the pressure was off me.

Fran will then be ready to compete in London in 2012, and I fully expect her to be challenging for medals.

Those Olympics will change British sport, which is something we desperately need, and for Fran to be part of that will be phenomenal.

Sharron Davies MBE won the 400m individual medley silver medal at the Moscow Olympics in 1980 at the age of 17