Mr Willson, who was a care worker, was attacked in Longcroft Park, Durrington, on Easter Sunday last year.
After a trial lasting more than a week, a jury, on Thursday (May 12), found two boys under the age of 16 – who cannot be named for legal reasons – guilty of causing grievous bodily harm with intent.
Harry Furlong, 18, of Horsham, was cleared of causing grievous bodily harm with intent but found guilty of causing grievous bodily harm.
Mr Willson, 47, was beaten with a wooden log and left with 'severe' brain injuries and multiple fractures, Lewes Crown Court at Hove was told. He was not expected to survive and has made a 'limited recovery'.
Speaking outside court after the teenagers were convicted, Annie said: "I feel relieved that it's over but now we have to find our new normal.
"We are all distraught. We have lost someone who was an amazing person.
"Even though I say we've lost him, he's still here. So it's very difficult.
"He doesn't fall into any category."
Mrs Willson said the lack of remorse from the children involved in the attack made her 'quite angry', adding: "At the end of the day, there's nothing we can do about it.
"They are how they are and behave how they behave.
"Above all we are Willsons and we, at all times, will behave with dignity and strength."
The defendants claimed, when giving evidence, that they were acting in self-defence against Mr Willson and alleged that he came armed with a log.
Mrs Willson said her husband was attacked after he 'went to rescue a little boy'.
She added: "He was not the kind of person to hurt anybody. If he had taken a stick round there, he would have dropped it when he saw they were children.
"He was the calmer one out of the two of us. I was the feisty one. He would have said lets go, lets leave it.
"That's how I know they weren't telling the truth because that's not Alan."
Detective Inspector Chris Rambour, of the Surrey and Sussex Major Crime team, read a statement outside court.
He said: "This was a sickening and violent assault on an innocent man, who simply stepped in to help a young boy who was hurt and upset.
"The injuries Alan suffered shows this was a sustained and prolonged attack. The people responsible for this clearly intended to cause serious harm with their actions and have not shown any remorse since.
"I would like to thank Annie and the rest of Alan's family for their bravery and dignity they have shown throughout this heartbreaking ordeal.
"I can only hope the result of court today brings some comfort to them and allows them to move forward and focus fully on Alan's recovery.
"I would also like to thank our team of investigators who worked so hard to build a strong case and the witnesses who came forward to help bring those responsible to justice."