She wants to raise awareness of the work being done by Glasgow's Prince & Princess of Wales Hospice as she becomes the face of its Christmas appeal, Light Up A Life.
Her dad John died of cancer in January.
The Rutherglen's Trinity High S1 pupil said: "I wanted to do something because of all the help they gave dad, and it's a good charity.
"If my dad knew I was doing this, he'd be over the moon.
"I think it's what my dad would have wanted."
She will join hundreds of families in remembering lost loved ones by sponsoring a Christmas light.
The appeal aims to raise £25,000 by illuminating lights at the Carlton Place hospice – a Georgian townhouse overlooking the River Clyde – and on a Christmas tree in Central Station.
Maria has already submitted her remembrance message to be read out at the Light Up A Life carol concert hosted by Sally Magnusson at St Andrew's Cathedral, just across the river from the hospice, on December 9.
The youngster's voice is heavy with emotion as she reads her dedication: "Dad, you were the best dad in the world, always there supporting me during my life.
"I love you forever."
Maria and lingerie tycoon Michelle Mone OBE joined forces to officially launch the festive fundraising campaign today.
The East Kilbride-based underwear entrepreneur added: "I'm very happy to lend my support to the Light Up A Life campaign and pleased that I can help such a worthwhile cause.
"The Prince & Princess of Wales Hospice carries out highly commendable work and I would like to encourage people from our city to lend their support by buying a light in this campaign in memory of a loved one."
Maria found out that her dad's condition was terminal on Boxing Day of last year.
Her parents had wanted her to enjoy Christmas before telling her that his treatment wasn't working and that he didn't have long to live.
The hospice staff proved invaluable in helping Maria through her grief.
Maria created a digital photoframe of his favourite pictures for him to watch when he struggled to communicate.
She recalls how nursing staff sang John his favourite songs during his final days.
Retired engineer John was 60 when he eventually lost his battle against the kidney cancer.
He had tried to stay positive throughout more than two years of treatment, continuing to do normal activities such as taking Maria cycling, swimming and ice-skating.
He had fought through the pain barrier to ensure that he could attend her Christmas play at school last December.
Since her father's death, Maria has embarked on a fundraising drive that has generated hundreds of pounds.
The South Lanarkshire girl and her classmates made a DVD based on P7 leavers' journey through the town's St Columbkille's Primary. This sold to more than 70 pupils and teachers in aid of the hospice.
She has also sold her handmade jewellery to friends and family, raising £100.
And through joining the Wiseman Welly Walk around Bellahouston Park in March – raising a further £100 – Maria, who takes great comfort in seeing her dad's name adorning one of the leaves in a tribute tree plaque in the hospice cafe, has discovered that she isn't the only child whose life has been devastated by cancer.
Maria said: "When I went to the Welly Walk, I thought I'd maybe be the only child there.
"But seeing all those people there for grandparents or parents who they'd lost made me realise that I'm not the only one it has happened to."
Maria's mum, Roseleen Lafferty, who was separated from John, said: "Her dad was so proud of her. She was the apple of his eye. The nurses here were great because Maria could come in to see her dad anytime and give him a cuddle.
"Maria said the whole experience of her dad dying was awful, but she was so pleased that it was in a place like this.
"The difference it made to Maria is invaluable."
Light Up A Life was founded in 1994 as a way to celebrate the hospice's 10th anniversary.
With the help of many celebrities, the appeal has raised more than £400,000 for the hospice in its 18 years.
The Evening Times is backing Brick By Brick, a campaign to build a much-needed £15million Prince & Princess of Wales Hospice on proposed site at Bellahouston Park.
The purpose-built facility would provide dedicated care for those aged 15-25 with life-limiting conditions.
The hospice must raise £2.8m annually from fundraising and voluntary donations to provide care for patients and their families.
lTo dedicate a light, call 0141 429 9840, visit www.ppwh.org.uk/donate/light-up-a-life or fill out the form, right.