Just what she would have wanted! Rita Ora to perform in Rome as part of Mother Teresa's canonisation celebration

Rita Ora is set to perform in Rome this weekend at a concert in advance of this weekend's canonisation of Mother Teresa of Calcutta.

A week-long series of events will culminate with a Mass on Sunday where Pope Francis will declare the Albanian-born nun a saint. 

The 25-year-old singer told US TV presenter Jimmy Fallon that she was performing at the Vatican during an appearance on the Tonight Show. 

Singer Rita Ora told Jimmy Fallon on The Tonight Show that she will be performing in the Vatican as part of the canonisation celebration for Mother Teresa of Calcutta this weekend

Pope John Paul, left, fast-tracked Mother Teresa for sainthood after her death in 1997

Mother Teresa, pictured, spent 50 years working with the 'poorest of the poor' in Calcutta

Mother Teresa was given the Nobel Peace prize in 1979 for her work with the poor in Calcutta.   

Tens of thousands of people are expected for the canonisation ceremony Sunday for the tiny, stooped nun who was fast-tracked for sainthood just a year after she died in 1997. 

Pope John Paul II, who was Mother Teresa's greatest champion, beatified her before a crowd of 300,000 in St. Peter's Square in 2003.

Francis has made the canonisation the high point of his Jubilee of Mercy, a yearlong emphasis on the church's merciful side. Francis has an obvious interest in highlighting Mother Teresa's mercy-filled service to outcasts on the periphery, given that her life's work exemplifies the priorities of his own pontificate.

Mother Teresa spent 50 years working with the poorest of the poor in Calcutta. 

Born Agnes Gonxha Bojaxhiu in Skopje, in what is now Macedonia, Mother Teresa joined the Loreto order of Roman Catholic nuns in 1928. 

She was traveling from Calcutta to Darjeeling in 1946 when she decided to start the Missionaries of Charity order. Since its establishment in 1950, the order has set up hundreds of shelters that care for some of the world's neediest, people she described as 'the poorest of the poor'. 

When she died on September 5, 1997, at age 87, hundreds of thousands of local people poured out into the streets to bid farewell. 

Pope Francis declared the curing of Marcilio Andrino, centre, of a viral brain infection was a miracle linked to Mother Teresa allowing her to be declared a saint. Andrino is pictured with his wife Fernanda and Sr Mary Prema Pierick, Superior General of the Missionaries of Charity

Mother Teresa, pictured right as a young nun learning English in Dublin, established the Missionaries of Charity order in 1950 to work in Calcutta with the 'poorest of the poor'

Gautam Lewis, a polio victim abandoned by his parents as a child and rescued by Mother Teresa, has long believed in the nun's sainthood, though it won't become official until Sunday.

He said: 'She used to consider all of us as her children. She was our angel guardian.' 

At 7, Lewis was adopted from an orphanage run by the Missionaries of Charity and moved first to New Zealand and later England. Lewis, 39, now runs a flying school for people with disabilities in the United Kingdom.

But the nun remains the most important influence on his life.

'Mother gave me a destiny to have a different life.'

For him Mother Teresa's canonization is 'just a formality. To most of us, most people in Calcutta, Mother is already a saint'.  

Brazilian Marcilio Andrino was diagnosed with a viral brain infection and given little chance of survival by medics.

Andrino's cure, declared a miracle by Pope Francis earlier this year, was the final step needed to declare Mother Teresa a saint. 

He travelled to Rome this week with his wife as part of Mother Teresa's canonisation. 

He said: 'Fernanda and I are just normal people within God's people. God didn't choose who to send down his mercy to, just like Mother Theresa, who cared for everybody without any distinction.'

According to the official account, Andrino was in a coma and dying on December 9, 2008 from a viral brain infection that had resulted in multiple abscesses and an accumulation of fluid around the brain.

Surgery was scheduled for 6:10 p.m. but the anaesthetist couldn't immediately intubate him. When the surgeon arrived a half-hour later, he 'found the patient inexplicably awake and without pain', according to the postulator of Mother Teresa's cause, the Rev. Brian Kolodiejchuk. 

Kolodiejchuk said Fernanda had been praying for Mother Teresa's intercession specifically during the half-hour when her husband was supposed to be in surgery.

Polio victim Gautam Lewis, pictured, said Mother Teresa cared for him at an orphanage until he was adopted by a family in New Zealand. He described the nun as his 'guardian angel'

She said: 'Marcilio was fine. He was sitting up. He was talking in intensive care (at the hospital) and I realised that he was cured, that Mother Teresa had interceded on our behalf and cured Marcilio. This was confirmed by the exams which proved the reduction of the abscesses and the disappearance of the hydrocephaly, making us sure that operations and drainage were no longer needed.'

Andrino has since resumed working and is in good health - and despite tests showing he had become sterile, has had two children since.

She added: 'Every time I look at Marcilio and our children, I feel very grateful. I am very grateful to God.'