The charity will emphasise the 'innocence' of Zoe Mace, whose sister Jodie had Down's syndrome before her death earlier this year, to demonstrate that there is no reason to fear children with the condition.
Mace, hailed by media in her local Oxfordshire as 'the next Charlotte Church', will release a CD entitled Songs for my Sister on 6 June to raise money for the charity.
'We hope that hearing a child saying "don't be scared" will encourage the public to look beyond the learning disabilities and physical appearance of people with Down's syndrome,' said comms officer Amy Darlington.
It is the first time the charity has used a child to front its Down's Syndrome Awareness Week, which runs from 6-12 June and is being promoted by The Forster Company. Darlington said Mace would appeal to women aged 25 to 45.
'We hope the story will enable us to reach young mothers, who may give birth to Down's syndrome babies,' said Darlington.
'Many mothers find out they are carrying a Down's syndrome baby before they give birth, which throws up massive, complex issues and can be very scary,' she added.
It will use case studies to raise awareness of the condition and demonstrate how sufferers can lead rewarding and fulfilling lives.
National and regional media are being targeted, along with women's titles.