Dallas, Texas(CNN) -- Financial troubles and despair over her husband's death were weighing heavily on the mayor of a Texas city who apparently killed herself and her daughter last week, her close friend told CNN.

"I think that the weight of it all became too much for her," said Doug Stover, who preceded Jayne Peters as mayor of Coppell, Texas. "She felt unfortunately, for her, this was the only option she had."

Police in Coppell said last week that Peters shot and killed her 19-year-old daughter before turning the gun on herself.

In an interview with CNN's Don Lemon on Saturday, Stover described Peters as "a very anti-gun person" and said she had borrowed the gun from a friend, claiming she needed it for a self-defense class.

"The way she died and the ways she behaved in the last days of her life were not characteristic of the way she lived," he said.

CNN affiliate KTXA reported that Peters faced foreclosure on her home at least twice this year. Ultimately, according to the Foreclosure Listing Service, the home was not foreclosed on, KTXA said.

Coppell City Manager Clay Phillips told the affiliate that the city was looking into expenditures charged to Peters' city-issued credit card to see if there were any financial improprieties.

Stover said close friends only learned of Peters' financial struggles after her death.

"She never opened up to anybody about her own problems," he said.

The Dallas County Medical Examiner's Officer ruled Wednesday that the mayor's death was a suicide and her daughter's a homicide.

Police found Peters, 55, and her daughter Mary Corinne Peters, 19, Tuesday evening after city officials asked them to check on the family's welfare when the mayor did not show up for a scheduled council meeting.

An envelope containing a note and a key to the two-story house had been left on the front door. Three other notes were found inside the house.

The outside note warned officers of what they would find inside, The Dallas Morning News reported.

One of the suicide notes said that her 19-year-old daughter hid her pain from her friends, according to The Dallas Morning News, and that mother and daughter "were lost, alone and afraid."

Police told the News the notes gave no clues as to what led to the shooting, but rather provided instructions on, among other things, how to care for the family's pets. Two dogs were found in the house, the newspaper reported.

Peters was elected mayor in May 2009 and had been a member of the city council since 1998. Her husband died of cancer in January 2008.

Coppell, 16 miles northwest of Dallas, has a population of 39,000.

CNN's Don Lemon contributed to this report.