Obituary: Clara Mullen, of York, who has died aged 12

Despite being severely disabled and confined to a wheelchair, Clara Mullen had a "zest for life" and was "the most joyful person you could ever meet", said her mother Sharon, of Bishopthorpe, York.

She added: "Clara was lovely inside and out. She was an absolute joy to look after."

Clara attended St Aelred's RC Primary School in York and also Applefields school, where she made many friends.

At her funeral on Tuesday at St Aelred's RC Church many of her school friends sang in the choir, led by one of Clara's favourite teachers Mrs Feehan.

Clara with mum Sharon and dad Isaac and sister Eliza-Jean

Clara had a love of music, said her mother, as well as animals. She was devoted to her pet dog Bertie and loved her pup Ralphie, who joined the family at Christmas, as well as Larry her rabbit.

She adored horses too and enjoyed going horseriding at a disability centre at Shipton By Beningbrough.

Clara horseriding

"She loved doing anything - she was really competitive," said her mother.

She said Clara had been a healthy baby and toddler but had become clumsy around the age of four. "We went to the GP and the hospital and they told us she had an incurable condition, eventually telling us it was probably Mitochondrial Disease, but they were not 100 per cent sure."

The condition meant that Clara lost the ability to walk, talk and eat and relied on a wheelchair and feeding tube.

Sharon said: "It was a difficult time but she was always smiling and never let anything get her down. She had a zest for life and loved school and her friends. She tried very hard at everything."

Clara leaves her mother as well as dad Isaac and elder sisters Eliza-Jean, 15, and Lailah, 21.

Sharon said the family have many special memories to treasure including trips to Disneyland Paris and to Lapland. "She loved snow," she added.

Clara was also able to go on pilgrimage to Lourdes twice with thanks to the HCPT group, said Sharon.

The family wish to thank everyone who helped Clara during her life, especially St Aelred's School and medical professionals, particularly her physiotherapist Juliet, her occupational therapist Ruth, and staff at York Hospital, especially Ward 17.

Sharon said: "St Aelred's were amazing with her. All the teachers and her friends loved her. They put in a lift so she could stay there for junior school and did everything they could so she could stay at that school. They really nurtured her through her illness."

Clara with her dog Bertie

They wished to thank the local children's hospice Martin House also for its support and for the gift of a "cooling blanket" which allowed the family to bring Clara home after she passed away at York Hospital.

Her death was caused by an underlying condition linked to her illness, said Sharon.

Clara is buried at Fulford Cemetery, where a mass of flowers have been laid in her memory, some in the shapes of unicorns and rainbows.