Bettina Rowley told 7:30 that her two children Charlotte, 5, and Frederick, 3, had developed a high temperature and dry coughs in only a few hours.
The family lives in Fussen, in Germany, and on a warm day the children had been playing in the garden, until it reached the evening and they both looked really run-down.
In the two hours to follow they both had temperatures over 40 degrees - at this point Bettina did consider that her children had contracted coronavirus but thought "surely not".
But, in 24 hours, they had developed a dry cough too, which made Bettina contact her doctor to get the children tested.
Within 48 hours results showed both children tested negative for the flu and positive for coronavirus.
Bettina said: "On that day when they were positive, the health authorities called us and I said, ‘Look, I don't know what to do. I can't control their temperatures. They are starting to drink less and less’".
She was advised to take her children to the hospital, where she was allowed to self-isolate in a room with her children.
She explained that Charlotte stopped being able to taste and both children's white blood cells were so low, it meant they had no immune system left at all - she said they were lucky it never made it to the lungs.
The nurses taught her how to use the medical equipment in the room, as they only wanted to come in, in an absolute emergency.
She said: “They are always saying kids don't get sick. Now you are in hospital with both of your kids. You feel very, very lonely. Yeah. Very scared.”
Andrew Steer, who leads the infection and immunity research team at the Murdoch Children's Research Institute in Melbourne, said: "Because the disease appears to be mild in children, it may be actually that there are more cases in children".
Charlotte and Frederick have now recovered from the virus.