Lee Primmer, who met Ashlee Good when she was the captain of the Victorian Country under 18 side he was coaching back in the early 2000s, said he was devastated to hear of her death.

"She played with the Mermaids back in 2002 or 2003 with my two daughters," Mr Primmer said.

He said she was an incredibly talented and respected player, who usually played point guard or shooting guard.

"She was a gun," Mr Primmer said.

Off the court she was a "lovely, caring person" who would stay at the Primmer household after playing home games in Warrnambool for the Mermaids.

She lived in Melbourne during her season with the team and would catch the train to games in Warrnambool.

"It was probably through my connection with the state team that she decided to play with the Mermaids," Mr Primmer said.

"I gave her a call and asked her if she would like to play and she became a drive-in, drive out player when we had home games."

Mr Primmer said Ms Good was an incredibly selfless person.

"What she did for her baby typifies the type of person she was," he said.

"I think everyone in Australia knows how special she is for what she did in the last few minutes of her life.

"She is one in a million and she always was."

Mr Primmer said his thoughts were with Ms Good's family.

"It wasn't a very good day yesterday when I found out," he said.

Lester Pickett, who was the coach of the Mermaids at the time, said he was shocked and saddened.

"She was a lovely person," Mr Pickett said.

"You wouldn't hear a bad word about her.

"It's so sad for her family and her partner - I hope the baby is doing well."

Ms Good, 38, defended her baby from the knife-wielding man in the tragedy that killed six people on April 13.

The osteopath died after Joel Cauchi, 40, attacked dozens of people - seemingly at random - at Westfield Bondi Junction on Saturday afternoon.

She was rushed to nearby St Vincent's Hospital in a critical condition but died that night.

Her nine-month-old daughter was also injured during the mass stabbing and remained in intensive care on Sunday after undergoing emergency surgery.

Dr Good, the daughter of former North Melbourne AFL player and board member Kerry Good, was remembered by her family as a "beautiful mother, daughter, sister, partner, friend" and an "all-round outstanding human".

Two brothers, who did not give their names, told Nine News they helped stem the bleeding from the mother and child's wounds after the woman thrust the baby into their arms begging for help.

Dr Good's family thanked the duo after they "held and cared for" the baby when she was unable to do so herself due to her injuries.

"We are struggling to come to terms with what has occurred," they said in a statement.

South Australian Premier Peter Malinauskas, who went to school with Dr Good's partner Daniel Flanagan, said it was "incomprehensible" that such a beautiful family had been so "aggressively affected" by the tragic events.