[1][3][4] She has cerebral palsy,[1] and, at the age of three, was encouraged by her mother to join a group for disabled swimmers to strengthen and relax her muscles.

[1][3] While Johnson was on the aeroplane to the 2008 Summer Paralympics in Beijing, her mother died after a long battle with cervical cancer.

[3] She repeated her breaststroke success at the 2009 event, breaking the world record in the process,[3] and also picked up two individual medley bronze medals.

[3] She won gold in the 100 metre breaststroke at the 2008 Summer Paralympics,[1][3] eleven days after the death of her mother, dedicating the victory to her memory.

[1][3][2] Johnson's successes were recognised when, in April 2011, she was given the honour of laying the final tile in the competition pool at the London Aquatics Centre.