Some support is available. Young carers are entitled to assessments from their local council to look at the impact on their health, education and wellbeing.

“When young carers get these it can make a real difference,” said Andy McGowan, the lead on young carers at the Carers Trust.

“But it takes many years of caring before they are actually identified. And then the support in place to help is patchy, it really depends on where you live.”

McGowan, who was a young carer himself to both his parents, says even when help is given to the young in the form of respite breaks, peer support and counselling, the underlying issue – the caring demands being placed on them – is often not addressed.

“The threshold to get adult social care from councils to relieve the caring burden is so high, many don’t get help. Until that is addressed, the inequalities young carers face will not be tackled.”

The NHS could do more, he added, particularly in terms of preventative and early support for things like substance misuse and mental health, which are also contributory factors to the caring responsibilities young carers have.

“Often young carers are left to fight their own battles for too long – and so school and their own health come second,” he said.

In July, the government published an action plan for unpaid carers which included measures to support young carers, including improved help in schools and joined-up support between the NHS, social care and education.

Other parts of the UK have their own policies – in Scotland, for example, there is a dedicated young carers’ grant.

“Through our new national care service, this government is determined to build a system that recognises the extraordinary contribution of unpaid carers, supports them better and, in particular, helps young carers,” a government spokesman told the BBC.

For families like the Brittons, more help cannot come soon enough.

“I worry about the impact caring has on Ava-Grace,” said Karen.

“She has had to grow up very quickly – that has had benefits, she is calmer and more mature than many girls her age and she has a real strength about her. But Ava-Grace and others like her need more help and understanding.”