It is lunchtime in a small primary school, and the head is sitting down to eat with half a dozen nine-year-olds when a thought occurs to her. She knows that one of the children at the table is adopted, and that the previous day, the girl in question - let’s call her Carrie - had been to court to have her adoption made legal. This had obviously been a special occasion, and something she is certain that Carrie wants to share. And so she brings it into the conversation.

What slips her mind, however, is that Carrie has chosen not to tell any of her peers that she is adopted. No sooner does the head make her well-meaning announcement than she realises her mistake. But it is too late. Carrie is mortified.

The incident highlights one of the classic issues faced by adopted children and their adopters, and one of the pitfalls for their teachers - the question of how such sensitive information, with all its potential for causing bullying and stigmatisation, should be managed in school. Who should be told that a child is adopted? At what stage should they be told? And who should do the telling?

Sarah Pepys, adoption and fostering services manager for Parents and Children Together (PACT), a voluntary adoption agency in Berkshire, Buckinghamshire and Oxfordshire, believes that parents themselves are often torn on the issue of disclosure.

“There is a wish among adoptive families for a child not to be labelled,”

she says. “But nor do they want the child’s needs to be unknown. It’s a balance. Sometimes people will say that they need to get to know a teacher before they share information, and maybe they feel that if they don’t talk about it too much outside the family, it won’t be an issue.

“But for some children, it’s a considerable issue, and schools can be crucial in helping the child move on. Schools provide a sense of security and structure and clarity - and that’s just what a lot of these children need.”

The key to success, says Ms Pepys, is a good working partnership between adoptive parents and the school, with clear, open and free communication from the outset. PACT advises adopters to visit a school before a child begins, and to try to gauge how the needs of children generally are understood before posing some of the particular issues faced by their children. Parents are also advised that every school will have someone - often the Senco - who is identified to work with looked-after children.

A teacher who is aware that a child is adopted, and who is also alert to emotional events that may be taking place outside school, will be less likely to misunderstand the child’s behaviour should difficulties arise, says Ms Pepys.

“What we’re saying to teachers is, if you just see this child as naughty, the problem can’t be managed from that perspective. It’s about having a bit of information available to you. So talk to your Senco and ask what happens to children when their early development has been delayed and muddled. If the child’s in front of you, you need as many clues as possible as to how to manage them.

“We often find that teachers aren’t alert to the fact that a child whose chronological age is six is only managing emotionally at a three or four-year-old level, because of their early trauma experiences. And as adoption workers, we’re often asking schools if a child can stay down for a year so that their emotions can catch up.

“There is quite a bit of research now which indicates that the early growth rate of children’s brains can be affected by how much emotional stability they have. For a number of adopted children, their early life experience wasn’t stable, so by the time they go into school, they don’t have that level of self-discipline, organisation and concentration that you would expect.”

Even when an adopted child goes on to secondary school, says Ms Pepys, their development might still be lagging behind that of their peers. “That level of organisation, commitment to homework, managing your environment and independent learning is all confused if emotionally you’re still insecure.”

And at this stage, the sharing of personal information with other children also becomes a highly sensitive issue. “We know that children digest different information in different ways at different stages. We find that children of two, three and four bandy the word ‘adoption’ around like a lollipop, and they’re all too happy to share it with their friends at school because it’s special and they’ve been told they are special.

“But when children get a bit older and they get a bit more sensitive, they may want to use the knowledge that they are adopted as a bargaining point, or they may wish to hide it. What we would say to teachers as well as adoptive parents is that you need to talk to your child about what their cover story is going to be.”

A cover story - a version of one’s personal history that appears consistent, while revealing no more information than the teller feels comfortable with - is a useful tactic that enables adopted children to keep control of unexpected situations. Ideally, such a story is prepared in advance, and agreed with key members of staff. Had this been done in Carrie’s case, the unfortunate lunchtime incident might not have occurred.

But as Carrie’s mother points out several years after the event, it’s not always that simple - particularly when, as in Carrie’s case, a sibling has also been adopted and attends the same school.

“We were advised to set up a story with the girls before we sent them to school,” says her mother. “But it was difficult to get them to understand and to agree that they needed to stick to it. In the end, we just left it up to them to do whatever they wanted to, and they told different stories.

“We were clear to the school about the girls being adopted, and we were also clear that we didn’t want everybody in the school knowing unless it was necessary, and that the girls would tell people that they wanted to.

But what happened was that the older sister told all of her friends and Carrie didn’t tell anybody. The head knew at the beginning that the girls weren’t necessarily telling people, but she’d forgotten.

“For heads, it’s a case of remembering what the picture was at the beginning, and in the case of a family, trying to aim for some consistency, so that everybody has the same picture.”