The sentence cut was part of Indonesia's Independence Day and comes after President Susilo Bambang Yudhoyono granted Corby clemency in May and slashed five years from her 20-year prison term.

Prisoners have to demonstrate positive moral development, including taking part in religious activities, and show regret for their crime

But Corby's sister Mercedes said securing her release would be a lengthy process. It is understood Schapelle will have to serve her parole in Indonesia.

"It's not a straightforward parole, but we are hopeful," Mercedes told the Herald Sun.

"We have just got to wait and hope that the process isn't going to be too long."

Mercedes said Schapelle was stable but still reliant on anti-psychotic medication.

"She's just in her own little world, but doing OK."

Corby was convicted of drug smuggling after she was caught in 2004 trying to import 4.1kg of marijuana into Bali.

Corby’s mother Rosleigh Rose told The Australian Corby was cautiously optimistic her application would be successful.

"She's quite positive, yes, but she says, 'Don't get over-excited, Mum'," Ms Rose said.

“She just keeps to herself more, she does a lot of painting and she reads a lot now."