Police say Maria Miranda, 41, called her boyfriend and threatened to kill herself and her daughters, and then they disappeared May 1. They were found safe in Arizona Monday morning.
Police said they believed Miranda had taken her children on a bus with her.
Since making another suicidal phone call Saturday, Miranda's cell phone was no longer working. Detectives believe at that point Miranda was out of battery power.
Miranda lives in a first-floor apartment on the Southwest Side. Neighbors say she spent her time taking care of her two daughters, Victoria, 19, who is mentally challenged, and Mariana, 1. Neighbor Alicia Mata says Miranda rarely left the building.
"Always when I come in, she is at home with the baby and other girl," said Mata.
"She made a phone call to her boyfriend and said that she was going to end it all, and she was tired, and she was going to kill herself and her girls," said Det. Pamela Childs of the Chicago Police Department.
Childs says that phone call came the first day Miranda went missing. Police say the mother of two made a similar threatening phone call to her boyfriend Saturday, and that is when he filed a missing persons report.
"The only real contact that we have is her boyfriend; he explains that she is kind of anti-sociable in the neighborhood, she doesn't have a lot of friends, doesn't really know a lot of people in the area, and he came home from work one day and she was gone," said Childs.
Neighbors say the boyfriend has gone door to door asking for help.
"He told me he is scared - he don't know where she went - he is petrified. He don't know what happened," said neighbor Bill Howe.
Police said Miranda took few items with her.
"She does not drive; she has no money; she does have a backpack with a few baby items in it," said Childs.
In addition, Miranda does not have debit or credit cards. However, police said she was carrying her passport and her 19-year-old daughter's passport.