Schapelle Corby was found guilty of trafficking four kilograms of marijuana into Indonesia.

Schapelle Corby was found guilty of trafficking four kilograms of marijuana into Indonesia.

Schapelle Corby's family is angry that a convicted heroin trafficker received larger cut to her sentence than their loved one.

Corby, 34, and Renae Lawrence, 33, have had their jail terms cut - by five months and six months respectively - as part of Indonesia's Independence Day celebrations.

Corby's uncle Shun Hatton said if Schapelle had pleaded guilty, she would be out of the Bali jail by now where she lives in a seven-bed cell with 12 other women.

"It really shows the justice system over there when someone with heroin strapped to their body gets six months and Schapelle only gets five months (reduction)," he said.

Lawrence is one of the so-called "Bali Nine," heroin smugglers. Corby was found guilty of trafficking four kilograms of marijuana found in her bodyboard bag when it was searched at Bali's international airport in 2004.

Lawrence, from Newcastle in NSW, was sentenced to life for her part in the 2005 plot to smuggle more than eight kilos of heroin from Bali to Australia.

Corby, from the Gold Coast, was sentenced to 20 years jail.

Mr Hatton said the family were "really pinning all our hopes on a pardon on humanitarium grounds but that could last forever.

"If she had pleaded guilty she would have been out by now but she won't because she is not guilty.

"If she had pleaded guilty she would have got eight to 10 years."

Mr Hatton, who last visited his niece in June, and said the high dosage of anti-depressants was wreaking havoc with her system.

She has put on weight, has bad skin and is 'quite grey' but dyes her hair black.

"The doctor said in any other circumstance he would not prescribe such a high dosage (of anti depressants)," said Mr Hatton.

"But there is not much else we can do."

Mr Hatton said the family was not very hopeful of getting parole and was more focused on a pardon.

- with AAP