Lord Justice McCloskey backed a prosecution bid to stop Sharon Harland’s release from custody after new information cast doubt over claims she is currently pregnant with her sixth child.
Harland, 44, is accused of killing 75-year-old Daniel Guyler, who was found with serious injuries two years ago and died nearly 10 months later.
A second woman, 33-year-old Rhona Gracey, is also charged with his murder.
The Public Prosecution Service mounted High Court appeals after a magistrate granted bail to both defendants last week.
On Wednesday the challenge to Gracey’s release was dismissed, with the judge citing “positive” progress in her life over the last year.
But he held there was a risk of Harland re-offending or attempting to interfere with witnesses.
Emergency services discovered Mr Guyler in the Termon Street area of Londonderry on July 23, 2018.
He never regained consciousness, dying in hospital on May 1, 2019.
The pensioner had sustained a head injury, and a doctor concluded that he had either fallen repeatedly from a height or been attacked.
Gracey, from Coven Street in Belfast, and Harland, of Baltimore House in Derry, were arrested last week and jointly charged with his murder.
They are also accused of robbing Mr Guyler of £400 he had in his wallet.
Although no-one saw the pensioner being assaulted, witnesses alleged the two defendants were with him shortly before the incident.
At the time both women lived in hostel accommodation and drank in the area of the alleged attack, according to the prosecution.
The pair had been detained at the time, but initial assault charges were not pursued.
It was contended that forensic evidence now links them to Mr Guyler.
Previous courts heard Harland is currently pregnant with her sixth child.
However, Lord Justice McCloskey was told information from a prison source raises doubts about her condition.
“At this stage this court is bound to form the view that two successive courts have been seriously misled about an important issue,” he said.
With Harland currently in quarantine due to the Covid-19 emergency, no blame was directed towards defence lawyers unable to take further instructions.
Confirming the outcome in her case, Lord Justice McCloskey ruled: “I accede to the prosecution appeal and I reverse the bail decision of the District Judge.”