In an interview with WAGA-TV, Atlanta, Bonnie Flood of Cumming, Ga., said she spent a month with Bush in Boca Grande, Fla., giving him 6 hours of daily instruction, Politico reported Friday.
She told the Fox affiliate the former president started out painting dogs and graduated to landscapes as he became more comfortable with the medium.
Three of Bush's paintings became public when a hacker posted items gleaned from family email accounts. Two of the paintings appeared to be self-portraits -- one showing the lower legs and feet of someone in a bathtub and the other the upper back and head of a man in a shower, his face partly visible in a shaving mirror.
The third was a picture of a stone church.
Flood was more enthusiastic about Bush's works than most critics who reviewed them.
"He has such a passion for painting, it's amazing," Flood said. "He's going to go down in the history books as a great artist."
Bush is following in the footsteps of President Dwight Eisenhower and British Prime Minister Winston Churchill, both enthusiastic painters.
Flood said she was unsure what to call Bush and finally settled on 43, which is how the 43rd president signs his work.
"When I really wanted him to do something, I would say, 'Mr. President, you know that you don't do it that way," she said.