In the Hobart Supreme Court, Anna-Lyce Maree Olding pleaded guilty to one count of manufacturing a controlled drug for sale, one count of perverting justice and one count of failing to report the killing of Brendan Marriott.

In early 2010, she began a relationship with married father-of-three Noel Percy, of Bagdad, who she allowed to use her garage to manufacture methylamphetamine. 

She also bought items for his drug manufacturing using her eBay account.

Justice David Porter said Percy had a falling out with his friend, Mr Marriott, about drug money and that he shot and killed Mr Marriott on or about December 2, 2010.

He said while Olding did not have any foreknowledge of the crime, Percy spoke to her immediately after using words such as: ``It's done, I've done it . . . He's gone; I can't believe I did that.''

``The defendant consoled a shaken Percy and they went to the property where he showed her the trench which contained the body concealed by debris,'' Justice Porter said. He said Percy burnt the body and placed the remains in a blue bucket.

Police had been investigating Percy's drug manufacturing and the disappearance of Mr Marriott, and, in March last year, police searched Percy's Bagdad property.

Percy was in Queensland at the time and his wife told him about the search. He immediately rang Olding, asking her to tip the contents of the bucket into the water and destroy other evidence linking him to the murder and to manufacturing drugs.

Justice Porter said Olding tipped out the contents of the bucket but had not rinsed it.

Police found the bucket, and forensic examination revealed the ashes were from human remains.

Justice Porter said Olding's upbringing was disrupted and that her involvement in the aftermath of Mr Marriott's death came due to her ``great love for Percy''. Justice Porter also accepted Olding was remorseful.

For the charge of manufacturing a controlled drug for sale, Olding was sentenced to 12 months in prison with a non-parole period of six months.

For the charges of perverting justice and failing to report a killing she was sentenced to 18 months' jail with a non-parole period of nine months.

Percy committed suicide in May while in prison without having been tried for Mr Marriott's murder.