Charlotte is singing at the Winter Olympics closing ceremony

But the dozens of underage partying youngsters were told not to do anything to upset her squeaky-clean image and were allowed only non-alcoholic drinks.

The birthday bash, with a DJ on hand to keep people on the dance floor, came just hours before she was due to fly off to North America where she will sing at the closing ceremony of the Winter Olympics.

Charlotte's parents Maria and James picked up the bill for the taking over the Latino's nightspot in Cardiff's Cafe Quarter.

Extra security was laid on to keep out the gatecrashers at the event which saw the teenage guests dancing until 0030GMT, with the star of the night often choosing the music.

Charlotte has since flown out of Britain and will spend her birthday night, 21 February, with two girl friends at the trendy Moonba nightspot in Los Angeles.

Bread and butter work: the teen singer as Saturday girl sandwich maker

She then flies on to Salt Lake City where she is singing in the closing ceremony of the Winter Games on Sunday.

Nightspot owner Giovanni Malacrino, 44, confessed it was more difficult looking after 100 excited schoolchildren than 2,000 rugby fans.

He said: "We were serving 2,500 people on Saturday at the Wales-France rugby match, that was easier than doing a birthday party for 100 16-year-old children who think they're adults.

"We had to set up extra security and we had loads of gatecrashers.

"Word had spread amongst the kids that Charlotte was having her party.

Checked ID

Because we are a licensed premises we had to make sure everyone was safe.

"There was a security guard in front of the bar to make sure people buying alcohol had ID to show they were over 18."

Charlotte's parents booked the party two months ago and made it clear they did not want alcohol being served to the youngsters - staff were asked to check the ID of anyone trying to buy alcohol.

Charlotte sent out invites to her friends and school friends at the private's Howell's School in Llandaff, Cardiff.

Church is developing a more mature image

The play list for the evening included her favourite song, Get UR Freak On by Missy Elliot.

Despite her international fame and fortune, Charlotte is keen to keep in touch with her school friends.

Last month she helped out in a Cardiff sandwich bar on a Saturday morning to raise money for cancer research.

She admitted that she often worked in the city centre takeaway to help her friends there on busy days.