Troy and Matthew Richardson were with family, including their father, at The Cabbage Tree Motel on the afternoon of July 29 last year celebrating Troy's buck's party when they got into a dispute with another group over the use of the pool table.

The argument descended into a verbal stoush, with CCTV footage of the incident showing Troy's twin brother, Terry Jnr, walk towards a male in the group named Danny Quirk and push him in the chest.

Quirk's girlfriend, Emily Mortlock, immediately throws a glass at Terry Jnr, hitting him in the face.

The footage shows Troy move away with his brother the check if he's okay before returning to the fray, approaching Quirk from behind and punching him in the right side of the head while his back was turned.

The duo then get into a fight as Matthew comes to his brother's aid and also assaults Quirk, before the two warring parties are separated by hotel security.

Terry Jnr was taken to hospital where he underwent surgery to remove glass fragments from his face.

His injuries included a severed tear duct, a lacerated eyeball which required five stitches, bruising to his eyeball, a 2cm cut above his left eye, a 1cm cut on his eyelid and multiple lacerations to his face from shards of glass.

Mortlock was charged with reckless wounding, to which she pleaded guilty.

She was sentenced to six months' jail, which was confirmed on appeal.

Meanwhile, police charged Troy and Matthew with affray. The pair had been due to face a hearing in Wollongong Local Court on Wednesday but pleaded guilty to a lesser charge of common assault in a deal with prosecutors.

The pair's lawyer asked the court not to record a conviction in either case, saying both brothers had no prior criminal record, were otherwise of good character and were genuinely remorseful for their actions.

However, Magistrate Michael Stoddart said a conviction was warranted given the serious nature of the offence.

"The community shouldn't have to put up with it," he said.

"People should be able to go to these licensed premises and enjoy themselves without this alcohol-fuelled violence."

Magistrate Stoddart recorded a conviction against both brothers and placed them on a 12-month community release order. The pair were supported in court by family including their father.