Bronwyn Streader had drunk the champagne, two glasses of red wine and a gin and tonic while on medication, her lawyer told Melbourne Magistrates Court yesterday.

Alex Lewenberg said Streader, 30, was a human rights and refugee activist in Japan, with a doctorate in Japanese culture.

"When I fly Qantas economy I'm lucky to get three glasses of orange juice," Mr Lewenberg said, "but if you're blonde and good-looking you get 20 glasses of champagne."

Streader pleaded guilty to charges of interfering with a crew member, smoking and not wearing a seatbelt during landing. The court heard she had boarded a Sydney-bound flight in Tokyo on March 28 and was seen drinking various types of alcohol.

The prosecution said Streader was served about five alcoholic drinks in a five-hour period. About halfway through the flight she was told to stop smoking, but she lit another cigarette before her packet was confiscated.

When a flight attendant later found evidence she had smoked in a toilet, the captain sent his co-pilot to deliver Streader a formal warning.

"Krieger [the co-pilot] attempted to give [her] the warning but [she] refused to listen and instead reached out and grabbed a pen from the left pocket of Krieger's shirt," said the prosecution's summary tendered in court. "I'm going to sue you. I'm going to take all your names," she had said, and when Krieger reappeared she grabbed his identification on his shirt.

During the aircraft's descent, Streader left her seat, refused to return to it and stood in the galley during landing, after which she was arrested.

Mr Lewenberg said his client had been seriously assaulted in Tokyo, and on the flight she had been affected by a combination of alcohol and medication.

In his sentencing remarks, the magistrate, Lance Martin, said Streader had been bitterly disappointed with the Japanese authorities' response to her assault. Mr Martin said although misbehaviour on aircraft could put lives at risk, he accepted that Streader, who flew from Japan for yesterday's hearing, was traumatised and had acted out of character.

She was put on a 12-month bond, without a conviction, and ordered to pay $600 to the court fund and $400 in costs.