"You've got to feel for her. She's such a beautiful girl and that's all her dreams shattered."
The couple were due to wed on June 17 in Gouard's home town and were holidaying in France in the lead-up to the ceremony.
"They were such a lovely couple together. We were so lucky to have her in the family."
St George said all of Beau's family were to attend the wedding and were set to travel in May and early June to Europe.
Instead Beau's father Neil St George and his three brothers Clyde, Luke and Steve together with Neil's partner Annie flew to France last night to bring Beau home.
His two younger sisters Rachael and Denise stayed in New Zealand to support their mum.
Liz St George described her second-born son as popular and thoughtful.
"He was a very caring, very kind kid. Everyone loved him. Even from when he was little. He was always making sure everyone else around him was okay. He was quick to make friends."
She said his wide circle of friends would be shocked at the news.
"Beau's friends will be absolutely devastated. He was very popular. He was a wonderful father, a beautiful father and loving partner."
Beau was born in the far north and lived in Hokianga before the family moved to Aria in the King Country to follow Neil's career as a champion shearer.
He was good at and loved sport as a child, excelling at cross country running.
The shearing lifestyle rubbed off on Beau after the family moved back up north to Mitimiti and when he completed schooling at Whangarei Boys' High School, the teenager eventually followed in his father's footsteps.
He spent time shearing in Wollongong, south of Sydney, before basing himself in South Australia.
St George, who lives on the Karikari Peninsula, said her son met his long-term partner, about eight years his junior, in the shearing shed.
"Herminie got a work visa in Australia, an agricultural visa, and she was rousing and he was a shearer."
The couple owned a house together in Mangonui and rented it out, planning to travel some more while their daughter was young.
It was too soon to known when Beau would be brought home or when a funeral could take place.
St George said she had not been informed of details surrounding the crash and did not yet know where Beau was driving to when it happened at 6am local time in an area known as Le Bois de L'Ours.
French media reported the crash happened in an area prone to accidents.
They reported the driver of the other car, a local man, also 33, received minor injuries and was taken to Manosque Hospital.
