A sibling to Peggy Sue Thomas and a potential witness in her first-degree murder trial was found dead in her Marysville home late last week.

Details on the death of Brenda Stackhouse-Gard were few on Tuesday. Stackhouse-Gard, a half-sister to Thomas, has family in Washington and Idaho.

Thomas is expected to be charged with first-degree murder next month in the Dec. 26, 2003 shooting death of Russel Douglas of Langley. Her arraignment was postponed Monday in Island County Superior Court after Craig Platt, her attorney, cited issues that needed to be resolved before the arraignment proceeding.

Contacted after the hearing, Platt declined to elaborate on the issues.

Thomas now faces arraignment on Oct. 24.

A spokeswoman for the Snohomish County Medical Examiner’s Office acknowledged Tuesday that the body of a Marysville woman had been brought in Sunday, but declined to offer details, pending contact with the family of the deceased.

Island County Prosecutor Greg Banks said the death of Stackhouse-Gard did not appear related in any way to the murder of Douglas, but it was something that local authorities needed to examine.

“Under the circumstances, we are concerned,” Banks said. “We have been in contact with investigators to determine whether or not there were suspicious circumstances in her death.”

“I have no evidence to believe her death was connected to Russel Douglas’ murder, but we would be remiss in our duty not to look into it,” Banks added. “Brenda Gard was a potential prosecution witness and had cooperated with us in the past.”

“I am sorry for her family’s loss,” Banks added.

Banks said that Stackhouse-Gard was not a main witness in the case, but might have been called in response to the defense of Thomas, perhaps as a witness to rebut testimony on Thomas’ character.

Thomas was arrested on a charge of first-degree murder in early July. Detectives claim that she helped lure Douglas to his death to a remote property south of Freeland with a promise of a Christmas gift for Brenna Douglas, his estranged wife.

Thomas worked with Brenna Douglas in her Langley hair salon called Just B’s. Authorities claim that James “Jim” Huden, a one-time boyfriend to Thomas, shot Russel Douglas in the head while he was visiting Whidbey Island with Thomas during the Christmas holiday season in 2003.

Huden was arrested in June in Veracruz, Mexico, after nearly seven years as a fugitive.