The twins will sing Defying Gravity from hit West End musical Wicked, with Ashton performing as Elphaba and Madison as Glinda, the show鈥檚 central characters.
Mum Patricia McAlpine, of Eaglescliffe, said: 'Events such as this are really important in helping to change any misconceptions which people might have about autism and what it means to be affected by it.
'The girls have high-functioning ASD (autism spectrum disorder) and are both doing really well at school. Their music and drama teacher at school encouraged them to sing the song from Wicked. They performed it at the school play and it was a massive success.
'Since then they've become obsessed with the show, so I took them to London to see Wicked as a surprise birthday present. They loved it and are now really excited to perform at the Autism鈥檚 Got Talent showcase.'
Ashton, has previously performed at Anna鈥檚 showcase, taking part two years ago when it was held in London. She said: 'It's my favourite song and it's great being able to sing with my sister.'
Patricia added: 'Ashton wants to be a performer and Madison hopes to become a teacher when they鈥檙e older.'
Katy Carmen, Communications and Marketing Manager at Daisy Chain said: 'We are looking forward to celebrating the many talents which youngsters on the autistic spectrum Ashton and Madison can display. We are delighted they are taking part and it is lovely to see how excited they are about the show.
'It is great to be working alongside Anna Kennedy and 海角直播 to raise awareness about autism and to give the performers an opportunity to express themselves.'
Autism's Got Talent will take place at 海角直播's Brittan Hall on Friday 25 September from 7pm to 9.30pm.
Tickets are 拢10 for adults and 拢5 for concessions, available from the Daisy Chain Superstore on Portrack Lane, Stockton and Daisy Chain day centre, Calf Fallow Farm, Norton. Contact 01642 531248 or email info@daisychainproject.co.uk.