The 42-year-old, herself an accomplished golfer with a five handicap, taught Danny to play when he was 8 and said the secret of his success was dedication.
Speaking at the family home, which is lined with trophies and sets of golf clubs belonging to the eldest of her three sons, Mrs Lee put paid to rumours that Danny might return to play for his native Korea. "No, of course, New Zealand," she said.
When the Herald visited, Danny's father, Sam, was asleep after staying up all night to watch his son play in the amateur final, and Ben, 16, had taken the day off school after the excitement of his brother's win.
The excitement was also being felt elsewhere in Rotorua, and perhaps nowhere more than at Rotorua Boys High School, where Danny is a Year 13 student.
The school was already revelling in having four former pupils at the Beijing Olympics, including cycling bronze medallist Sam Bewley, and is now counting Danny among the ranks of its greatest sports achievers.
"He's got to be the next Tiger Woods," said his classmate and deputy head boy Geoff Howes.
"His whole life is devoted to golf."
Since 2002, the school has run a golfing academy, after producing world champions in 2000 and 2001.
Danny joined the academy in 2003 and coach Mark Lavery said he was marked by an ability to stay extremely calm under pressure.
"He's got the mental strength, the way he executes the shot. He's virtually got the nickname Danny the Machine because he just hits the ball so straight.
"I've never seen someone execute a golf ball so consistently. Once he gets on to a birdie trail, shooting under par, you can't stop him."
Mr Lavery said Danny's physical strength was improving as he matured, and he'd give Woods a run for his money at the US Open next year.
"Danny's got the attitude of 'I'm going to beat him'. He's got that self-belief ... He'll be chasing Tiger, he'll have him in his sights."
Danny had once been shy, but a large number of victory speeches after his many competition wins had brought him out of his shell and he was no longer afraid of public speaking, Mr Lavery said.
Dennis Rollinson, manager of Springfield Golf Club, where Danny is a member, said it used to be difficult to get the 18-year-old "to say boo to anybody", but as his game developed, his shyness had receded.
He said Danny liked to have fun and every time the teenager walked past his office, he would bang on the window and pull a funny face.
Mr Rollinson said Danny was also very loyal to the club and when he won the NZ Amateur championship in Hamilton last year, he had said the fairways were not as good as Springfield's.
He was also upset when he was invited to play in a Korean tournament and they tried to brand him as a local, rather than as a New Zealander.