Lillian Marie Lapier was arrested in the Great Falls courthouse after officers reportedly found her with meth on Thursday morning.
A Cascade County Sheriff's deputy was sent to the courthouse where Lapier was being held in custody.
A bailiff told the deputy that he received a call from a probation officer advising him that Lapier was at a hearing at the courthouse, and that there was an outstanding warrant from Idaho for Lapier.
The bailiff took Lapier into custody and placed her in a holding cell at the courthouse.
When the deputy arrived, the bailiff showed him Lapier's belongings, which included $130 in cash.
Inside a crumpled-up $100 bill, the deputy reportedly found a small plastic baggie with a white powdery substance that tested positive for meth.
He asked Lapier if the money was hers, and she told him it was, according to court documents.
Lapier's warrant from Idaho was for allegedly violating her probation and was issued on May 20.
She currently has a case pending in Cascade County in which she is charged with criminal possession of dangerous drugs, tampering with or fabricating physical evidence, endangering the welfare of a child, obstructing a police officer, and several traffic offenses.
In that case, Lapier is facing charges after she was involved in a car crash in Great Falls and then ran away from the scene with her daughter.
Lapier is charged with felony criminal possession of dangerous drugs for Thursday's incident.