The woman then returned home, where police found the daughter dead in the bedroom. A silver handgun was found nearby.
Mary Hansen told police that both she and her daughter suffered mental illness and that both "wanted to die," according to charges.
Mary Hansen, who was treated at a hospital, was arrested the day after the shooting and booked into the Salt Lake County jail, where she remained Thursday in lieu of $1 million bail.
Mary Hansen reportedly had health issues and financial troubles.
Audrey Orrillo, who had been a friend of Mary Hansen for some time, said the mother lived on Social Security benefits, had fibromyalgia and was behind on paying the property taxes on her home.
According to the Salt Lake County Treasurer's Office, Hansen owed $8,819.62 in unpaid taxes and has been delinquent since 2008.
Orrillo said Hansen had moved with her daughter from California and used inheritance money to pay cash for her West Jordan home but had gotten behind on the taxes.
Orrillo said the daughter had few, if any, friends and took online classes instead of traditional school. She said the mother and daughter stayed at home and rarely went out.
"They were all [that] each other had," Orrillo said.
The combination of stresses on the mother may have caused her to snap, Orrillo said.