Anna-Lee Kehoe had been engrossed in a game when she suddenly called out to her mum that she could not breathe. The youngster then collapsed.
Anna-Lee - who had asthma - was taken to hospital by air ambulance and put on a life-support machine, but had tragically been left brain dead from a lack of oxygen. Her devastated family made the decision to turn off the machine the following day.
Her dad, Tony told the Sun: "I was speaking to Anna-Lee 10 minutes before and she was fine. She was playing on the Xbox then went to the toilet. When she came back she said she couldn't breathe and collapsed. We phoned an ambulance and her mum tried to do CPR on her but she never woke up again. They are not sure what caused it. As far as we know she was perfectly healthy apart from her asthma. She didn't even have the sniffles."
Anna-Lee's heartbroken big sister Robyn, 23, said: "She was already brain dead in hospital but they kept her on the machine until we could say our goodbyes. Anna-Lee was loud, bubbly and outgoing."
The family, from Bridport, Dorset, are now awaiting the results of a post-mortem.