"He wouldn't be who he is without you?" asked CBS News correspondent Jim Axelrod on "Sunday Morning."
"That's for sure," Ivana replied.
Ivana, who split with Trump a quarter-century ago, also said she was "very proud" of how their three children
together -- Donald Jr., Eric and Ivanka -- handled themselves during their father's presidential campaign "because they were articulate, intelligent."
Watching her children during the campaign inspired her to write her new book, "Raising Trump,"
When asked whether she or the President raised their children, Ivana Trump took the credit.
"It was definitely me," she said.
Raised in communist Czechoslovakia, Ivana Trump married Donald Trump in 1977, partnering with him on some of his most prominent real estate projects. The two divorced in 1992 in the aftermath of his tabloid affair with Marla Maples -- who later became his second wife and mother of their daughter, Tiffany.
Ivana Trump has since been married and divorced twice, and now maintains a jet-setting, globetrotting lifestyle.
"Well, she's -- I don't -- talk about her," Ivana Trump said of Maples, refusing to even call her by her name. "She's a showgirl. Never achieve anything in her life."
Maples, who was divorced from Trump in 1999, has played various roles in film, television and theater.
Trump says her relationship with the President's third wife -- first lady Melania Trump -- is a totally different story.
"I get along with Melania. Yes," Trump said.
When asked why she has a good relationship with Melania and not Maples, she responded bluntly by saying, "One, it's nobody. And the other one, it's first lady."
Ivana Trump also said she still talks to her ex-husband weekly
and has encouraged him in his Twitter habits.
"I said, 'I think you should tweet. It's a new way, a new technology. And if you want to get your words across rightly, without telling The New York Times, which is going to twist every single word of yours, this is how you get your message out,'" Trump said she told her ex-husband.
She also told CBS that the President offered her the ambassadorship
to her native Czech Republic, but turned it down to preserve her "perfect life."
"I was just offered to be the American ambassador to Czech Republic -- and Donald told me, he said, 'Ivana, if you want it, I give it to you,'" the 68-year-old said in the interview. "But I like my freedom. I like to do what I want to do, go wherever I want to go with whomever I want to go. And I can afford my lifestyle. OK, why would I go and say bye-bye to Miami in the winter, bye-bye to Saint-Tropez in the summer and bye-bye to spring and fall in New York? I have a perfect life."