Elisa Baker, who murdered and dismembered her 10-year-old disabled Australian stepdaughter Zahra Baker, has been sentenced in the US to 10 years' jail for conspiring to sell prescription pills.

Judge Richard Voorhees, in the US District Court in North Carolina, ordered Baker on Monday to serve the 10 years after she completes the 15- to 18-year sentence she received for the shocking 2010 murder of Wagga Wagga-born Zahra.

Baker was facing a maximum sentence of 20 years for the drug count.

Baker, 43, was originally facing seven felony drug charges and a maximum 140-year sentence for selling pills including oxycodone and hydrocodone from three homes between May 2006 to October 2010, including a trailer the family lived in and the rented house where Zahra went missing in October 2010.

In a deal in January, prosecutors dropped all but the one conspiring to distribute painkillers and anti-anxiety drug charge in exchange for Baker's guilty plea.

Zahra, who moved to the US with her father Adam Baker after he met Baker on the internet, had a tragic life.

At the age of five Zahra, suffering bone cancer, had her lower left leg amputated and lost her hearing.

Family members alleged her stepmother abused her before her death.

Baker was able to avoid a first-degree murder charge, and possible death sentence, by doing a deal with authorities investigating Zahra's murder.

Baker showed authorities where she dumped some of Zahra's body parts in bushland in return for a second-degree murder count.

An autopsy found Zahra's body was cut up with a saw.