Gymnastics: Tiny Tunney hoping to make it big this summer

Rebecca Tunney: 'I knew it was going to be huge and big but this was more than I expected' (Rex Features)

As Britain's youngest competitor, London 2012 was always going to be unlike anything Rebecca Tunney had experienced before and she happily confessed yesterday that it has already been an "overwhelming" experience.

The 15-year-old Tunney, who at 4ft 9in is also the smallest member of Team GB, has enjoyed a meteoric rise to claim a place in the five-strong women's gymnastics squad, who are targeting a top-five finish in the team event. Yesterday, Tunney faced the world's media for the first time too.

"Overwhelming," she said when asked how her first taste of an Olympic Games had been. "I wasn't expecting it to be like this. I knew it was going to be huge and big but this was more than I expected. [My teammates] have helped me through it, just tried to calm me down."

She is enjoying it though and neither she nor the team's performance director, Tim Jones, appears at all worried it may affect her once competition begins. "We have no real concerns that Rebecca won't be able to cope with the environment," said Jones. "She's a tough kid and we know she will do the job for us."

Tunney has been helped by having Beth Tweddle – or Tweedle as her place card at yesterday's press conference had it – and two other City of Liverpool clubmates in the squad.

Tweddle, chasing an Olympic medal to add to her world titles, yesterday confirmed she would be fit to compete, although she is still sleeping each night with a £3,500 ice machine attached to her troublesome left knee.

"My body is fully fit now," said the 27-year-old. "It was a bit touch and go with the knee, and I've proved to selectors I'm fully fit. I do still sleep with my ice machine, but luckily I've got a single room so I'm not keeping anyone else awake."