Ms Liber has taken out the Nikon-Walkley Portrait Prize in the 2014 awards for her photograph ‘‘Little Princess’’ which captured an intimate moment between the seven-year-old - who has Batten disease - and older sister Nataya.

The girls were dressed like little princesses ahead of a brush with royalty - a week later, on Good Friday, the Stone family met the Duke and Duchess of Cambridge when they visited Bear Cottage children’s hospice.

Battens is a fatal neurodegenerative disease, with a life expectancy of between eight and 12 years, and it has already taken Imogen’s speech and sight.

For Ms Liber, who has worked at the Mercury for 18 years, it was one of the hardest but most rewarding photos she has had to take.

‘‘It’s one of the most emotional jobs I’ve been to - it’s part of our job, it’s what we do but that doesn’t mean it gets any easier,’’ she said.

‘‘But it gave me a chance to do what I love - I love capturing the emotion, the moment, the feelings. If I can put all of those things into a photo then I know I’ve done my job.

‘‘It does feel nice to get recognition for that.’’

Meanwhile for Imogen’s parents - Lynda-Jane and Stephen - and their other children Nataya, 9; Isaac, 3 and Amelie, 1 - the photograph is ‘‘priceless’’.

Mrs Stone congratulated Ms Liber on Friday for the ‘‘well-deserved’’ award, and said she was grateful for the lasting memory of such a special occasion.

‘‘Sylvia just captured such a beautiful, emotive photo of our girls,’’ Mrs Stone said.

‘‘We were in tears while she was taking it - it’s something we will treasure, it is just priceless.’’

See all the Nikon-Walkley finalists