ENGLEWOOD, Ohio -

More than a month after an Ypsilanti mother's disappearance, a troubling find at an Ohio restaurant may be the first real clue. It was a handwritten plea for help possibly written by Tonya Jackson herself.

The note was found in the bathroom of a Steak and Shake restaurant in Englewood, Ohio, nearly 200 miles from her home in Ypsilanti.

Investigators called the note a significant lead, though they're not sure Jackson wrote it.

"They found a note written on toilet paper... Her name and another individual and that she needed help," said Sgt. Mike Lang, of the Englewood Police Department.

Jackson's Saab SUV is still missing. The note in Ohio said she was in a red Chevrolet Cavalier.

Nikita Evans is Jackson's sister.

"There's still no activity on her account, no ping on her phone turns up anything," said Evans. "She vanished."

Jackson is 42 years old, 5 feet 7 inches tall and weighs 180 pounds. She was last seen leaving the Knights Inn near Metro Airport, where she was meeting a male co-worker. Police said he is cooperating.

"For her to come up missing out of the blue like that, that's a big mystery to us," Evans said. "She was an everyday mom. Working, or taking kids back and forth to activities."

Related: Family desperate to find missing Ypsilanti mom

Investigators have no security video that verifies Jackson was in the restaurant where the note was found, and because it was hastily written on toilet paper, handwriting analysis is difficult.

"Any type of clue, anything we get we take very seriously because we don't know what to do," said Evans.