Lesotho's Appeal Court revoked her bail last week on suspicion that procedure was not followed correctly when her bail was granted.
Thabane was transferred to court, where she wore a fur coat and black protective anti-coronavirus mask, a Reuters witness said.
The date for a new bail application was set as June 6.
Lipolelo was estranged from Thomas Thabane at the time of the murder.
The case had been causing growing political instability in the independent mountain kingdom of 2 million people encircled by South Africa before Thomas Thabane resigned as prime minister last month.
He is also a suspect in the murder. He denies any involvement and has yet to be formally charged.