The heartbroken mother of Hannah Clarke has given shocking insights into her murderous son-in-law, telling an inquest he was "all for show", had no empathy and would use his children as punishment. 

Two years after her beloved daughter and grandchildren were murdered by her then son-in-law Rowan Baxter, Sue Clarke revealed her disturbing interactions with the man while he was married to Hannah. Baxter was originally from Tauranga and played for the Vodafone Warriors. 

Baxter murdered Hannah and their children Aaliyah, 6, Laianah, 4, and Trey, 3, as the family drove to school on February 19, 2020. 

Hannah Baxter's children Laianah (6), Trey (3) and Aaliyah (4). Photo / Getty Images / Facebook 

Armed with a knife and jerry can of fuel, he doused the car in petrol and set it alight. 

Sue Clarke on Wednesday told the court that she didn't initially like Baxter but warmed to him. 

But, after Laianah was born, his behaviour turned nasty. 

"He would call me names, he would tell me there's no reason for me to be at the gym," Clarke told the court. 

Clarke recalled an incident when Rowan was supporting her in the gym but dropped her, seriously injuring her face. 

Rowan Baxter, Hannah Clarke and their children. Photo / Supplied 

She said Rowan then "laughed" at her. 

"He told me to harden up, things like that happen all the time when you play football," Clarke said. 

The court was told that Baxter would punish his mother-in-law by refusing to let her see the children if Hannah "misbehaved". 

Hannah was not allowed to wear shorts or the colour pink. 

Clarke said Baxter would berate Hannah as "fat and lazy" in front of the children and at times criticised paying female members of the gym as "pigs". 

Sue Clarke said Rowan Baxter's behaviour would turn nasty. Photo / NCA Newswire 

Baxter would appear to act as a generous person "all for show" – shouting beers, coffee and lunches for his mates while spending the family's money. 

"I could never say what I thought (to him)," Clarke said. 

"He certainly didn't care for the children at all … never changed nappies, dress the children, get them breakfast, pack lunches or anything like that. It was all for show." 

Clarke said she was only aware that Baxter left a recording device in her Camp Hill home until witnesses gave evidence on Monday. 

The court was told that Baxter "abducted" Laianah on Boxing Day, taking her to northern NSW. 

During this time, Clarke said Baxter demanded that Hannah run his gym class in his absence, but she refused. 

Hannah told members on social media that she wanted nothing more to do with the gym, prompting Baxter to call and abuse her and shut down the whole business. 

Rowan Baxter was part of New Zealand Warriors 2005 squad. A Friend of Baxter's told the court of his jealous and controlling behaviour towards his wife. Photo / Andrew Cornaga 

When Laianah was returned, Clarke said she looked "traumatised". 

"Aaliyah was angry, the whole time … in her little mind, he'd been begging (Rowan) to put her down," she said. 

Clarke gave heartwarming tributes to each of her grandchildren – "articulate and bright" Aaliyah, "little middle and little dynamo" Laianah and "sporty" Trey. 

The inquest continues. 

How to get help 

If you're in danger now: 

• Phone the police on 111 or ask neighbours or friends to ring for you.
• Run outside and head for where there are other people. Scream for help so your neighbours can hear you.
• Take the children with you. Don't stop to get anything else.
• If you are being abused, remember it's not your fault. Violence is never okay.

Where to go for help or more information: 

Women's Refuge: 

Crisis line - 0800 REFUGE or 0800 733 843 (available 24/7) 

Shine: 

Helpline - 0508 744 633 (available 24/7) 

It's Not Ok: 

Family violence information line - 0800 456 450 

Shakti: 

Specialist services for African, Asian and Middle Eastern women and children. Crisis line - 0800 742 584 (available 24/7) 

Ministry of Justice: 

For information on family violence 

Te Kupenga Whakaoti Mahi Patunga: 

National Network of Family Violence Services 

White Ribbon: 

Aiming to eliminate men's violence towards women