HONOR, Mich. (AP) — The family of a suburban Detroit woman who disappeared in northern Michigan is offering $100,000 for information on her whereabouts, six weeks after they last heard from her.

Adrienne Quintal, 47, was reported missing last month from a family-owned cabin near Honor, about 20 miles (32 kilometers) southwest of Traverse City.

The last known communication with Quintal was through a family friend on Oct. 17, according to her sister, Jenny Bryson. She said Quintal called the friend at 2:34 a.m. to say she was involved in a shootout with two men who were outside the cabin while she was inside. The friend said Quintal explained that she shot one man in the face and the other shot at her, according to Bryson. She then urged the friend to call the police, Bryson told the Detroit Free Press on Friday.

But when the police arrived at the cabin at 3:15 a.m., they didn’t find Quintal, of Southfield, Michigan.

“It is gut-wrenching. I lay awake every night wondering where she is,” said Bryson, who lives in Macomb County.

Benzie County dispatchers found multiple bullet holes in the empty cabin and shell casings on the ground from what appeared to be multiple guns. The dispatchers found no evidence that someone had been shot or injured. But they found evidence suggesting shots were fired out of the cabin from the inside.

Authorities found Quintal’s 9mm handgun on the ground and her boots and cellphone on the roof.

“We’ve not ruled anyone out as a suspect or ruled out any possible theories on what could have occurred,” Sheriff’s Detective Lt. Troy Lamerson, adding that everyone is a person of interest and no one has been charged.

Lamerson said authorities theorize Quintal was abducted, had a medical problem that led her to believe there were people were after her and fled, or that she staged her disappearance to run away. Benzie County sheriff’s investigators remain on the case.

Bryson described her sister as “a beautiful girl,” who is the youngest of four siblings. She said Quintal has been a concealed pistol license holder for at least 10 years.

“It’s a total mystery how she vanished,” Bryson said. “And our family desperately wants some answers.”

The six-figure reward will run through Saturday.

Anyone with information can call Benzie County Central Dispatch at 231-882-4487 or Michigan State Police Silent Observer at 866-774-2345.