The defendant had been kicked out of the house by her mother and was there to pick up her belongings.
Hendra pushed past her mother to get into the house.
The woman fell to the ground and her daughter aimed a barrage of punches at her head.
When the victim went to the lounge to call police, Hendra and Webb followed, pinning her to a seat.
Both women punched her as she was restrained.
Eventually, the victim escaped to the kitchen but Hendra pushed her over again.
The defendant then picked up her mother's puppy and threatened to break its neck.
Webb was charged with assault and sentenced to four months' community detention and 150 hours' community work
According to defence counsel Brian Kilkelly: "despite the appellant and her co-defendant being charged with different offences, Judge Phillips ought not to have distinguished between them to the extent he did. The appellant says there was nothing to distinguish their roles in the attack and both were equally culpable".
However, Crown prosecutor Marie Grills said there was a clear distinction in the women's violence.
Justice David Gendall, in his decision released this week, agreed.
"The appellant began punching the victim in the hallway and pushed her down to the ground in the kitchen following the joint attack in the lounge," he said.
"Furthermore, the appellant had a clear level of premeditation here and it was she who instigated the attack. Ms Webb only joined in after it had begun."
Hendra also pleaded guilty to other charges: assaulting police, possession of class B drugs and theft.
Police found oxycodone on her during her arrest four days after the violence.
Five months later she was arrested for breaching her bail and kicked a police officer in the head while she was being assessed in hospital.
Hendra was given a final chance on bail at a Women's Refuge safe house in Gore but while staying in a shared property stole electronics, worth nearly $500, to sell for drug money.
"The appellant has not demonstrated that the sentence imposed was wrong or unjust," Justice Gendall said.
If it is an emergency and you or someone you know is at risk, call 111.
• Women's Refuge: 0800 733 843
• Victim Support: 0800 842 846
• Lifeline: (09) 522 2999
• Family Violence Info Line: 0800 456 450