The Oklahoma State Bureau of Investigation announced Beverly Noe was taken into custody in a traffic stop near Drumright. She was being held in the Creek County Jail.
Wendy Camp, 23, Lisa Kregear, 22, and Cynthia Britto, 6, vanished in 1992 after traveling from Oklahoma City to see Camp's son. The boy was living with his father, Chad Noe, in Shamrock.
At the time, Beverly Noe told investigators she drove the women and Cynthia from Oklahoma City to a Walmart in Chandler. No one at the store remembered seeing the group.
The bodies were located last year after Grover Prewitt Jr., Noe's brother, told investigators he had dug a hole for a septic tank on a property then owned by his mother, Ida. Ida Prewitt, who died several years ago, is also suspected of being involved in the killings.
Prewitt has been charged with being an accessory.
The identities of the skeletal remains were not positively confirmed until this year.