She achieved A* grades in French and history and As in geography, maths, English literature and English language.

The singer took some of her exams while on tour.

Her head teacher at Howell's School in Llandaff, Cardiff, Jane Fitz, is delighted.

"Charlotte has done very well," she said.

"To achieve the results she did on top of all her other achievements is miraculous.

She has worked very hard and we are delighted for her."

Cancer

Charlotte was in good company at the school, where one in three pupils taking GCSEs achieved straight As.

Another success story is that of Kiran Patel, who achieved good grades even though he missed all but two weeks of the past school year because he was being treated for cancer.

Despite his illness, he decided to go ahead with four of his GCSEs - English, maths and double science, and achieved grade Bs in all of them.

He was diagnosed with Hodgkin's disease about a year ago after finding a lump in his neck.

He only found out he was in remission two weeks before sitting the exams.

Kiran attends King Edward VI Camp Hill School for Boys in Birmingham and plans to study AS-Levels in biology, chemistry, physics and business studies there.

He explained why he decided to enter the exams, despite the painful treatment he was enduring and the stress of the illness.

"I felt it was up to me. I had worked so hard in the first year on coursework that I just didn't want all that hard work I had done to go to waste and not take the exams," he said.

"I felt like it was in me to do it even though I couldn't do all nine GCSEs. My teachers and parents said to me, `Look, you don't have to do it, you can just drop all nine'.

"After much deliberation with my parents and the school, I came to the decision to do just the main GCSEs."

Kieran hopes to go on to university to study "something like biotechnology", he says.