The baby was also found dead.
The body of Bush’s baby, Valkyrie Grace Willis, was found Wednesday, and Bush’s body was found Thursday in separate locations in Missouri, according to authorities in Benton County, Arkansas.
Bush had three other children, ages 8, 7, and 2, and was engaged to be married.
Amber Waterman is charged with kidnapping resulting in death.
She is accused of killing Bush, who was 31 weeks pregnant.
Waterman’s husband is charged with being an accessory after the fact for allegedly helping Amber Waterman dispose of Bush’s body.
They remain in federal custody pending detention hearings, which have not been scheduled.
Federal court records do not name attorneys representing the couple.
According to a federal court affidavit, Amber Waterman called herself тАЬLucyтАЭ online in order to meet Bush.
She allegedly persuaded Bush that she would give her a ride to a job interview.
Sometime between Monday and Wednesday, Waterman drove Bush from Maysville, Arkansas, to Pineville, Missouri, resulting in her death, prosecutors said.
Arkansas authorities said Bush died from a gunshot wound.
During a news conference on Thursday, Arkansas authorities declined to provide more information on how the baby died or where her body was found.
The federal complaint alleges Jamie Waterman helped his wife hide Bush’s body in a tarp, burn it in a fire pit behind their home and then dispose of the remains.
Ashley Bush was reported missing on Monday.
Her fianc├й told law enforcement that the couple met a woman they knew as тАЬLucy,тАЭ who said she would drive Bush to meet her supervisor at a Bentonville, Arkansas, company.
The fianc├й said that later he was waiting to pick up Bush when she and тАЬLucyтАЭ drove by in a pickup truck and didn’t stop.
He later found Bush’s phone on the side of the highway.
Benton County sheriff detectives later found a Facebook post of тАЬLucyтАЭ offering to give baby items to any moms who needed them.
When detectives questioned Jamie Waterman on Thursday, he told them his wife said she killed Ashley Bush and then led him to the body, according to the federal affidavit.
The Watermans could face state charges for two murders in Arkansas but that decision will be made after consultation with other jurisdictions, Benton County Prosecuting Attorney Nathan Smith said.
