Nancy Guthrie stayed home with her children before taking a job at a university, according to a blog post by her daughter, Today show host Savannah Guthrie.
Nancy, who is 84, has been missing for several days, and her disappearance has received national attention. She was last seen at her home in Arizona on Saturday.
Pima County Sheriff Chris Nanos said at a news conference on Monday that Nancy requires daily medication, and it could be fatal if she did not have the medication every 24 hours.
He said officials believe "that we do in fact have a crime scene, that we do in fact have a crime."
The sheriff also said there were things at the crime scene that indicated Nancy "did not leave on her own."
Nancy stayed home with the children while her husband worked as a mining engineer, Savannah said in a Guideposts blog post.
Savannah grew up in Tucson. Her father died of a heart attack when she was 16.
Savannah said Nancy got a job working in public affairs at the University of Arizona. She said the position "made tuition more affordable for my sister and me."
The home where Nancy resides has an estimated value of $1,097,449, according to realtor.com. Zillow estimated the home's value at $1,011,400.
The home was last sold in 1975 for $85,000, according to realtor.com. A mortgage release lists the home's address and states that the mortgage was executed by Nancy and her husband in 1975, according to county records.
Two news outlets have received an alleged ransom note, and law enforcement said it is investigating whether it is connected to Nancy's disappearance.
Local Arizona outlet 13 News said it received an email Monday night that appears to be an alleged ransom note. The outlet said it forwarded the note to the Pima County Sheriff's Department, and investigators are working to determine its credibility.
Nanos told CBS News that the news station agreed not to report on the note. He said it contained details about Nancy's home and what she was wearing that night, but he did not confirm whether those details were accurate or whether the note was legitimate, CBS News reported.
TMZ said it received what appears to be a ransom note for Nancy, but the outlet said it has not been able to verify it. Nanos told CBS News that TMZ reported on the note it received before contacting the sheriff's office.
The sheriff said the FBI has reviewed an alleged ransom note and decided to share it with Savannah, according to CBS News.
The Pima County Sheriff's Department said on Facebook that it is aware of reports circulating about a possible ransom note or notes regarding the investigation into Nancy's disappearance.
"We are taking all tips and leads very seriously. Anything that comes in, goes directly to our detectives who are coordinating with the FBI," the sheriff's department wrote.
Authorities had not located Nancy Guthrie as of Wednesday afternoon.
Savannah Guthrie, Today show host and daughter of Nancy Guthrie, in a statement posted on Instagram: "We believe in prayer. We believe in voices raised in unison, in love, in hope. We believe in goodness. We believe in humanity. Above all, we believe in Him. Thank you for lifting your prayers with ours for our beloved mom, our dearest Nancy, a woman of deep conviction, a good and faithful servant. Raise your prayers with us and believe with us that she will be lifted by them in this very moment. We need you. 'He will keep in perfect peace those whose hearts are steadfast, trusting in the Lord,' a verse of Isaiah for all time for all of us. Bring her home."
Pima County Sheriff Chris Nanos, at a news conference on Tuesday: "We have a lot of work in front of us. We have a job to do, and we have someone's life who is in jeopardy, and so job number one is we got to find her and we got to work hard to do that."
Anyone with information is urged to contact 88-CRIME. Tips can also be submitted anonymously by calling 520-882-7463, via the P3TIPS mobile app, and online at www.88crime.org. The sheriff's office is offering a reward of up to $2,500 for information leading to the arrest of the person or persons involved in the disappearance.