Murdered Sally Anne Bowman’s 21st birthday will be marked with the release of thousands of pink balloons.

On September 11, more than 1,700 people are set to join the Bowman family outside Allders in Croydon to mark Sally Anne’s birthday.

The event has been organised through social networking site Facebook, in the hope they will be able to draw a huge crowd for the remembrance ceremony.

Linda Bowman said: “We are really hoping for a big crowd. I won’t be there but my daughters and Sally Anne’s cousins will be. I may turn up but I plan to spend the day at my daughter’s grave. I can sit with her and see the balloons from there.”

Mrs Bowman has said she would like people to remember her daughter on her birthday by releasing pink balloons with a message inside so that Sally Anne can receive them in heaven.

“The family can look up in the sky and see how much people are thinking of them,” she said.

The Bowman family’s Facebook page has had a good reception although some people have tried to hijack the site thinking it is another Facebook house party.

A friend of Sally Anne’s sister Nicole Bowman, Kelly Taaffe said: “She was an angel, special to all who knew and loved her, she was talented, ambitious, and didn't deserve to be taken to heaven so quickly. God must have known she was special, he only takes the best.”

Sally Anne, who was born in Carshalton and attended Cheam High School, was attending the Brit School in Croydon before she was murdered.

Former chef Mark Dixie killed Sally Anne in 2005, stabbing her seven times and subjecting her to a horrific sexual assault.

Her partially clothed body was found by a neighbour early the same morning.

Throughout the trial Dixie proclaimed his innocence saying he drunkenly stumbled upon her dead body and had sex with it, but said he had nothing to do with her death.

He was eventually convicted of the killing and sentenced to 34 years in jail.