Samara Tulloch was just a teenager when her mother was shot and killed by her abusive husband in a McDonald's car park.

So the news that another Gold Coast woman, Teresa Bradford, was stabbed to death by her estranged husband on Tuesday hit her particularly hard.

Speaking for the first time about her mother's death in September 2015, the 20-year-old said her mother also endured years of abuse.

Samara Tulloch, now 20, has recalled how her father Steven shot and killed her mother Katrina back in September 2015 after years of abuse

'My dad broke her. He completely ruined her and she turned into this scared, overreacting woman,' she told the Gold Coast Bulletin.

'Mum was very much by herself. Looking back, Dad would overrule her decisions. He was very dominating and they are the little signs people should look for in a marriage.'

Ms Tulloch said her mother was never allowed to see her side of the family, and later in the marriage not even spend time with her friends.

Though she and her two brothers, aged 28 and 18, and their 15-year-old sister watch their dad psychologically abuse Ms Lock, the beatings always happened in private.

Mrs Tulloch said the relationship 'broke' her mother (left), leaving her 'a scared and overreacting woman' before she was killed (Samara pictured far right with her family)

Mrs Tulloch is now married and moved to Tasmania with her husband (pictured)

She said the siblings were out a lot because life at home was 'uncomfortable', and she now wishes they knew enough to stay home and protect her.

Like Ms Bradford, her mother eventually left and moved her family out of town, but a few weeks later agreed to meet him at the Helensvale McDonald's.

They had agreed to sign the divorce papers, but Stephen Lock planned the murder-suicide weeks in advance.

Ms Tulloch now lives in Tasmania with her husband and like the AVO that did nothing to save Ms Bradford, she thinks the system let her mother down.

Ms Lock was shot to death in the car park of the Helensvale McDonald's

Paramedics try to save Mr Lock but he died after killing his estranged wife

She laughs at suggestion battered women can easily up and leave, as her mother tried for months but Mr Lock always 'found ways to weasel his way back'.

Ms Tulloch said her mother was so scared of her husband she told no one about the abuse, even her children, and deleted all her text messages in case he saw them.

'If you think something's happening, just try to get them to talk. Mum wouldn't talk to anyone. Her whole life had been filled with mental abuse so she didn't know who to trust,' she said.