Maxine Carr could be free within days, after the Prison Service confirmed she has been recommended for electronic tagging by Holloway Prison's governor.
Carr could be tagged and released
Carr was jailed for three-and-a-half years at the Soham trial for conspiracy to pervert the course of justice and has served 18 months, 16 on remand.
She could be out "immediately" if prison boss Martin Narey approved her case, a Prison Service spokesman said.
However, her release could be blocked if it undermined public confidence.
Carr's papers were sent by the governor to Mr Narey, head of the Home Office's National Offender Management Scheme, a week ago.
"She has already reached her halfway point. She was at that stage sometime in
early January," a spokesman said.
"She could be out immediately if the decision is made to approve the governor's recommendation."
He added that Mr Narey's decision was expected "sooner rather than later".
If released from jail, Carr would be fitted with an electronic tag which would trigger alarms if she left
her house during a curfew.
Ed Willetts, the governor of the women's prison at Holloway, north London, approved Carr's application to join the scheme.
Upon release Carr could be placed under the witness protection programme where she could be offered a new identity and have an alarm placed inside her home.
Although Carr does not technically qualify for protection as she was not a trial witness, former police officer Terry Jones suggested it could still be offered to her to protect her own safety.
"The Home Office and the local police would apply witness protection to her because of the exceptional circumstances," he said.
Carr, 26, was convicted in December of conspiring to pervert the course of justice following the murders of Holly Wells and Jessica Chapman.
Holly and Jessica disappeared in their home village of Soham, Cambridgeshire, in August 2002.
Their bodies were found in a ditch near Lakenheath, Suffolk, 13 days later.
Carr's former partner, school caretaker Ian Huntley, was sentenced to life for their murders.
The house where he killed the girls is expected to be demolished in April, education authority officials have said.
Cambridgeshire County Council said arrangements were being made to have the house outside Soham Village College taken down during the Easter holidays.
A nearby storage hangar where Huntley tried to hide the girls' clothes after killing them will also be demolished at the same time.