A woman charged in a deadly 2012 house explosion agreed Tuesday to plead guilty to conspiracy to commit arson and to testify against at least two other people accused in the fiery natural gas blast that damaged dozens of homes.

Monserrate Shirley, who had pleaded not guilty after she and two men were charged in late 2012, appeared before a Marion County judge in a courtroom filled with current and former residents of the neighborhood marked by the blast.

Marion Criminal Court Judge Sheila Carlisle told Shirley she was taking her plea agreement under advisement, but stressed that it could be "months or years" before she decides whether to accept it because Shirley must fulfill her pledge to cooperate with prosecutors against the other defendants.

Under her plea deal, the 49-year-old woman would plead guilty to two counts of conspiracy to commit arson and prosecutors would drop 52 charges against her, including two counts of murder. She would have to testify against her former boyfriend, Mark Leonard, and his brother, Bob Leonard, as well as "any other individuals as yet uncharged" in the Nov. 10, 2012, explosion.

The deal would allow Shirley to avoid a possible sentence of life without parole, which she could face if convicted on the original charges.

Prosecutors allege Shirley and the Leonard brothers rigged the blast in her home on Indianapolis' south side as part of a scheme to collect $300,000 in insurance.

The late-night explosion killed a married couple — 34-year-old electronics expert Dion Longworth and his 36-year-old wife, second-grade teacher Jennifer Longworth. The explosion damaged more than 80 homes, several so badly that they had to be razed.

Prosecutors previously said the trio made one attempt to blow up the home that failed. But Shirley's plea agreement states that Mark Leonard and "an uncharged individual" had earlier tried to set a fire in Shirley's home.

Marion County deputy prosecutor Denise Robinson said after the hearing that Shirley has provided information that could lead to charges against others.

"She's already provided some information and we'll be continuing to talk to her," said Robinson, who called the plea "a fair resolution" that ensures Shirley's "cooperation against other defendants, charged and uncharged."

"From a prosecutor's perspective it means that we have now direct evidence of the crime. In other words, we have someone who was on the inside, who was a party to making certain observations, overhearing certain statements, who's now cooperating with the state," she said.

Shirley's attorney, Jim Voyles, declined to comment following Tuesday's hearing.

Carlisle asked Shirley that if she understood that under her plea she could face a minimum 20-year suspended sentence with probation and a maximum 50-year prison term.

"Yes, your honor," an emotional Shirley replied, her lip trembling.

Court documents said Shirley was facing mounting financial woes, including $63,000 in credit card debt. A friend of Mark Leonard's told investigators Leonard said he had lost about $10,000 at a casino some three weeks before the explosion, according to court documents.

Prosecutors have said that investigators determined that Shirley's home filled up with gas after a gas fireplace valve and a gas line regulator were removed. A microwave, apparently set to start on a timer, sparked the explosion.

Mark Leonard's trial is scheduled to begin June 4 in northern Indiana's St. Joseph County, where it was moved because of publicity. It's unclear when Bob Leonard will be tried.