She had to bang her fist on the head teacher's table and burst into tears of frustration to get a supply of large print books - which she had repeatedly been promised - to make reading easier for him.
Nicholas, 12, has cerebral palsy. He is unable to stand or walk and is totally dependent on his parents. But his mother was was told only recently that she was entitled to a month's respite care every year. She found out from a friend, not from Brent social services department in north-west London, one of the many agencies with responsibility for Nicholas.
Mrs Alcorn, who lives in Wembley with her husband Steven, a cameraman, also only discovered from a friend that she was entitled to disability allowances. And it was the Bobath day centre in East Finchley, where Nicholas goes for physiotherapy, that told her he was entitled to an electric, rather than manual, wheelchair.
Even though Nicholas is totally helpless at night and dependent on his parents, the Department of Social Security has stopped a pounds 5 a week night allowance. A pounds 5,000 grant to install a stair lift has also been turned down.
The Alcorns' experiences confirm the worst findings of the Audit Commission report, which highlights lack of co-ordination between agencies and bickering over who is responsible for children with disabilities. Mrs Alcorn was not even told her son had cerebral palsy until he was 10 months old, when her GP, assuming the hospital had told her, said he was sorry to hear about it.
She said: 'Everybody seems to want to do their best but they are totally hampered by the fact that one person hasn't a clue what other people are doing.'