Cornwall Council is appealing for more people to become foster carers.
There are currently 460 children in care across the county, three-quarters of them live with foster carers.
Neil Burden, for Children's Services, said the shortage of foster carers and rise in the number of children coming into care meant the need was urgent.
Sixteen-year-old "Anna" who has lived with foster carers since her mother died of cancer, said it takes young people time to settle in.
"It took me a couple of months to settle. I have been here 18 months and it feels like I have been here a lifetime to be honest."
Velda and Roger Smith have provided short breaks for children with disabilities in Cornwall for the past 11 years.
Mrs Smith said: "I said at the start that I wanted to care for older children from the age of four upwards and over the past 11 years have been involved with caring for around 35 children.
"Sometimes this has involved having a child once or twice a month, at other times we have looked after a child for one or two nights a week and at weekends. It depends on the needs of the child and the family."
Mr Burden, cabinet member for Children's Services, said it was "becoming increasingly difficult for us to find the right homes for these children".
"We urgently need more people to come forward to offer homes to these children," he added.