Charlotte Church celebrates her birthday at the University Hospital of Wales

Since shooting to fame six years ago with her single Voice of an Angel, she has become one of the world's hottest stars with a global profile to rival Britney Spears and Madonna.

But she is refusing to let a warts-and-all documentary featuring her ex-boyfriend and stepsister spoil her birthday week, describing it as "ridiculous".

Church will celebrate the day at a family party in Cardiff on Saturday night, although its exact location is a closely-guarded secret.

Speaking on Thursday, she was keen to play down rumours that Justin Timberlake and Robbie Williams would be there - something she said had disappointed her cousins when she had to break the news.

In the first of a three part series, BBC News Online talks to those closest to Church for an insight into her rapid rise to the top of the international celebrity A-list.

Standing in the centre of a crowded bar in Cardiff last Friday, Charlotte Church - arguably the world's most famous teenager - looks like any other youngster enjoying a night out with friends.

But her life could not have been more different to the hordes of office workers bustling along the Welsh capital's St Mary's Street.

How many others in the bar have sold more than 10 million albums around the globe, starred in a movie and performed in front of the Pope, Prince Charles and Bill Clinton (to name but three)?

Saturday marks 18 years since she was born on February 21, 1986, at St David's Hospital in Cardiff to 20-year-old Maria, who split up with Church's natural father shortly after.

There was a karaoke machine and Charlotte, who was only nine or ten, sang for two hours non-stop Family friend

Her first memory of taking the stage was performing Ghostbusters at a holiday camp in Caernarfon with her cousin when she was just three-and-a-half.

Back then she lived with her mother and stepfather James on Fairwater Grove East, and went to the nearby St Mary's Catholic Primary School, before moving on to the Cathedral School.

One family friend, who went to a party at the Church house after playing rugby with James, told BBC News Online the guests were given a sneak preview of her voice.

"There was a karaoke machine and Charlotte, who was only nine or 10, sang for two hours non-stop," he said.

"She wouldn't let anyone else have a go, but she did have a good voice even then."

Charlotte spent her early years on Fairwater Grove East in Cardiff

Church's first brush with fame came soon after, on This Morning with Richard and Judy singing Pie Jesu.

She followed that by upstaging her aunt Caroline Cooper on the Big, Big Talent Show with Jonathan Ross.

"They usually wouldn't let children on in case they got tongue-tied, but they let her do it because she had sung on Richard and Judy," Ms Cooper told BBC News Online.

"But she was nervous - we both were."

Her performances was spotted by Jonathan Shalit - who went on to become her manager - who rushed down to Cardiff where he met with Church and her music teacher Louise Ryan.

"She sang three or four songs - you could not help but be bowled over - she was awe-inspiring," he recalled.

"She had an amazing quality. And it was not only her voice, it was her personality.

Charlotte has left her girlish image behind

"I knew at that moment I could make her an international music star."

Mr Shalit then took her to see Sony chairman Peter Burger, and a record contract soon followed, along with a family trip to Disneyworld, paid for by Sony to help sweeten the deal.

But, despite her sudden fame, life continued as normal in Fairwater Grove East, according to neighbours who recall seeing no more of Church than her leaving in the morning for school.

But before long, any semblance of normality for the Church family would be gone as the Welsh schoolgirl instantly broke America.