Cooper and Johnson were wed just hours before the groom died on June 10 in eastern Kentucky. Cooper's three daughters by his first wife have gone to court, seeking to have the marriage nullified.
Their petition, filed in Lee County, calls it a "pretended ceremony" and "a mockery," The Lexington Herald-Leader reported Thursday.
"My dad would have never done this," daughter Shena Reece said. "We didn't even know they were married until we went to the funeral home the next day."
The daughters - Reece, Crystal Mays and Cassie Taulbee - contend Cooper, 59, was nearly dead at the time of the wedding and incapable of being married. Their petition says he was dying of esophageal cancer and was under the influence of narcotics and other medications.
"He couldn't raise his hand up. He couldn't speak," Mays said. "He couldn't recognize his children. ... His mouth just hung open."
Charnel Burton of Booneville, an attorney for Izetta Johnson Cooper, did not immediately return a message from The Associated Press seeking comment.
Cooper and Johnson, 52, had been married before, but were divorced about two decades ago. Cooper had been married three times before the deathbed marriage, Mays said. Johnson had been living with Cooper for perhaps a year and is living in his house today, Mays said.
"When he got cancer, she kinda floated back into his life," Mays said.
Johnson was appointed on July 14 to oversee the estate of Cooper, a laborer who drove a garbage truck for the city of Beattyville.
Among the assets listed in the court file were a 1998 Chevrolet truck, a 2003 truck, a house and land and other items valued at a total of $26,775.
Mays said contesting the marriage isn't about money or property, because Cooper wasn't rich.
"He was just a Southern man who worked all his life," Mays said. "He was a very proud man, and that's what it's about."
Information from: Lexington Herald-Leader, http://www.kentucky.com