A schoolgirl whose elder brother died a few years after sustaining a head injury has completed a triathlon for a charity supporting people who have suffered severe brain trauma.

Katrina de Martelly Seaman, 16, swam 750m in Teddington Pool, cycled 20km through Hampton and Richmond and ran 5km through Bushy Park on May 2, in less than two hours, and raised £1,453.24 for Brain injury is BIG.

Ms Seaman’s elder brother, Alex, suffered a severe brain injury in 2011 and died on September 18 2014, the day after Ms Seaman’s 16th birthday.

Ms Seaman, who is currently studying for her GCSEs at Teddington School, said she was delighted to be able to raise so much money for the cause.

She said: "Alex is what got me through it. At the beginning I thought other people are going through the same things we did and need support."

She said training hard for the Teddington Triathlon was often a welcome break from her revision.

She said: "It was a nice distraction to go for a run instead of revising so it was quite helpful."