Pauline (pronounced Perlene) admitted that she had slept with Tom, and in fact she may have been the one to have given him syphilis, since she began treatment in March, almost a month before Tom discovered he had the disease.
Pauline offered to look for Wilson Foster's mare (Laura's father) if he gave her a quart of liquor. She also bragged to local deputies Jack Adkins and Ben Ferguson that she had killed Laura Foster with Tom. She also remarked that she "would swear a lie anytime for Tom Dula."

When local deputies and others found Laura's body, and Pauline was imprisoned along with Ann, Pauline agreed to testify for the State

Sources:
West, John Foster. The Ballad of Tom Dula: The Documented Story Behind the Murder of Laura Foster and the Trials and Execution of Tom Dula. Durham, NC: Moore Publishing, 1970.
West, John Foster. Lift Up Your Head, Tom Dooley: The True Story of the Appalachian Murder That Inspired One of America's Most Popular Ballads. Asheboro, NC: Down Home Press, 1993.

Tom Dula - Ann Melton - Pauline Foster - James Melton
Dr. George N. Carter
Laura Foster - Colonel James M. Isbell - Zebulon B. Vance