PADEN, Okla. -- Investigators in Okfuskee County hope a few sheets of paper can yield the clues to help find Michelle Mooneyham-Davis, who has been missing for nearly two weeks.

VIDEO: Letter Might Lead To Clues About Missing Mom

A letter, supposedly written by her, just arrived on Sunday at the home in Paden she shared with her husband.

Mooneyham-Davis, 31, was last seen Aug. 7.

Her car was found on Highway 62, just a few miles away from the home. One of the car’s front tires was flat, the emergency flashers were on and the doors were locked.

“I think someone has my daughter and I hope they rue the day they ever even thought of it,” said Barnie Mooneyham.

Mooneyham said she’s convinced her daughter didn’t leave her family and had given investigators a sample of Michelle’s handwriting.

“I said, ‘I think you might need this if something strange happens,’ and something strange did happen,” she said.

A letter supposedly signed by Michelle was on her front door Sunday. Police believe it’s authentic.

“We believe it’s her writing and believe that she did write the entire letter,” said Okfuskee County undersheriff Derrall Summers.

Investigators are hoping a handwriting analyst can confirm that the letter is Michelle’s writing. In the meantime, her mother is encouraged and has a message for her daughter.

“Don’t give up. We will find you. The county sheriff is looking very hard for you and they will find you and will find whoever has harmed you,” Mooneyham said.

The family is planning a candlelight vigil to pray for Mooneyham-Davis Thursday at Wild Horse Park. Anyone with information about her disappearance is asked to call 918-623-1128.