It remains unclear if authorities believe the ransom notes are authentic.
The television presenter said that before the kidnapping, her mother was in “tremendous pain” and described how she had trouble walking.
“She can’t wander off,” she said.
During one of the more emotional moments of the interview, Savannah Guthrie described grappling with whether her mother was taken because of the television host’s fame.
This month, Pima County Sheriff Chris Nanos, who is leading the investigation, said authorities believe Nancy Guthrie was “targeted”, and they know the motive. But the sheriff declined to publicly say what it is, citing the ongoing investigation.
In the interview broadcast on Thursday, Savannah Guthrie described the immediate aftermath of her mum’s kidnapping as “a blur”. She said she, her brother and her sister spent their days praying for answers and crying for their mother.
She temporarily stepped away from her morning-show presenting duties after the disappearance and was not part of NBC’s coverage of the Winter Olympics as planned. She is expected to return to work, but it’s unclear when.
The family has indicated that they believe Nancy Guthrie may no longer be alive, but Savannah Guthrie said: “We need to know.”
The Guthrie family is offering a $1m reward, in addition to $100,000 pledged by the FBI, for information leading to Nancy Guthrie’s return.