Good Samaritan mum Lucy Knight new face of St John Ambulance's annual appeal

Lucy Knight - the good Samaritan who almost lost her life after going to the aid of a woman being mugged in Auckland - is the new face of St John Ambulance's annual appeal.

The wife and mother of six was punched in the head when she intervened as a young man tried to snatch an older Chinese woman's handbag outside Countdown at a shopping centre in Auckland in 2014.

The blow sent then 43-year-old Ms Knight to the ground, fracturing her skull.

She needed two emergency operations - one to remove a piece of her skull to relieve the pressure caused by the bleeding, and a second to replace the missing bone with a titanium plate.

Now Ms Knight, who has been hailed a hero and presented with several bravery awards, is praising the work done by St John paramedics and is urging others to support the charity.

In a video posted to the St John Ambulance website, she says: "St John kept our family whole."

She is also seen in the video meeting the paramedics that saved her life.

Assault victim Lucy Knight with the people who came to her aid. Pictured (from left) are Vanessa McCall, Lucy Knight, Hazel James and ambulance officer Phil Hewetson. Photo / Doug Sherring

Addressing them, Ms Knight says: "I just want to say how grateful I am to all of you, without you guys I would not be standing here today."

Her husband Peter Thomas also spoke on video about the work St John Ambulance did to save his wife.

"The surgeon told me that if St John hadn't done such a good job and got there so quickly, then we'd be looking at a completely different scenario.

"We were really grateful for the good work of St John and we know that our family is together because of what they did on that day."

Lucy Knight, with her husband Peter Thomas. Photo / Brett Phibbs

In the video, Mr Thomas also talks about what his family went through following the incident.

"It was very scary seeing her with her head bandaged, swollen, unresponsive. There were times there when we were wondering whether my wife, the kids' mum, would be back with us."

He choked back tears as he recalled a surgeon coming out of surgery after five hours and giving him the thumbs up.

"Which meant the world to us."

Ms Knight's attacker, 17-year-old Hendrix Hauwai, was jailed for four years and nine months in 2015.