"On the day she was leaving I felt very sad, but also glad that I’d been able to put something positive into her.”

Jeanette Threlfall describes how she felt as she said goodbye to Hayley, a teenage girl she cared for in her Bradford home.

The 13-year-old had been placed with Jeanette through the local Barnardo’s fostering agency and was Jeanette’s first placement as a foster carer.

The pair bonded straight away. “We walked to the park and started kicking a football around together,” says Jeanette. “I really enjoyed her company.”

The 46-year-old grandmother thought her love of children and experience working with them would stand her is good stead as a foster carer.

“I knew some foster carers through my church,” she says. “I’d just got my own home, and thought the time was right, so I applied.”

She chose Barnardo’s over other agencies. “I liked what I saw – their beliefs and vision sat well with me,” she says.

She underwent an assessment process and, six months later, was matched with Hayley, who needed a short-term placement before a place at a residential school became available.

“It is an intense process,” recalls Jeanette, “But it needs to be. What really impressed me about Barnardo’s is that they are determined to make sure they get the right match for you and for the child.”

Barnardo’s is this week holding its sixth annual Fostering and Adoption Week and is campaigning on the urgent need for more foster carers across the country.

The number of children in the care system in the UK has risen for the seventh year in a row to 90,000. For these children, the care and stability of a family home and a happy childhood is out of reach and their future could be just as uncertain.

There are not enough foster carers to care for vulnerable children – current calculations estimate 9,000 more are needed across the UK, and 750 in Yorkshire.

When she first arrived at Jeanette’s home, Hayley was not very confident, but quickly settled. The pair had fun on days out. “We went to City Park and other local parks,” says Jeanette. “I was given a pass which gave us free entry to museums and other attractions in Yorkshire. We really enjoyed ourselves.”

Jeanette wanted to build Hayley’s self-esteem. “Over time I talked about how it is possible to make a difference to your life,” she says. “It was a time of growth for both of us. Of course there were challenges, but it gave me new things to deal with, and is all part of growing as a foster carer as you go along.”

Since she left, Jeanette has kept in touch with Hayley and was moved when Hayley called her on Christmas Day. “It was lovely to hear from her,” she says, “Hayley will always be welcome here.”

Jeanette receives 24-hour support from Barnardo’s workers. “They are really supportive and friendly and there’s a lot of training on offer which helps you to understand why a child may be acting in a certain way. If there is anything I’m unsure about, I give a quick call or text to a social worker.”

Barnardo’s is looking for people with patience and commitment to provide a stable home for the most vulnerable children in the care system, in particular those aged ten and over, children from a black and ethnic minority background, sibling groups and disabled children. There is no upper age limit, although there is a minimum age of 21.

Jeanette’s next placement was 11-year-old Sally. “We met a few times before Sally moved in. She has really settled and her school has said that in the past few months she has matured and is flourishing,” says Jeanette.

Both she and Sally are hoping that the placement will become permanent.

“She is part of the family now,” adds Jeanette, who loves her role, and the satisfaction it brings. “I think you need to be empathetic to other people and you need to want to share your life. I think that the biggest thing you can give a child is self worth. If anyone out there is considering fostering, I would say it is so rewarding. Just go for it and ring Barnardo’s.”

Steve Oversby, director of Barnardo’s in Yorkshire, says: “Being a foster carer is a life-giving profession and offers the opportunity to create strong and positive memories and foundations for the most vulnerable children in our society.”

To find out more, ring 08000 277280, or visit the website barnardos.org.uk/fostering. The names of placement children have been changed.