The 'My Way' crooner left Nancy - the mother of his children Nancy Jr., Frank Jr. and Tina - in 1951 to strike up a relationship with the actress, and in later years admitted he had made a mistake.
Nancy Jr. - who was 10 when her father left - said: ''I said, 'If you had it to do over again would you have left?' He said no.''
However, the 75-year-old singer insists her mother never held a grudge against her ex-husband, who died in 1998.
She said: ''She still loves and adores him, definitely.''
And Nancy herself enjoyed a good relationship with Ava, and is also ''very close'' Frank's third wife, Mia Farrow, despite their volatile marriage.
Speaking of her dad's third reunion, she said: : ''He said: 'I don't know that this will last but I'm going to try.' ''
In 2013, Mia claimed Frank was actually the father of her son Ronan, not director Woody Allen, but Nancy insists the remarks were just a ''silly joke''.
She told The Times newspaper: ''Mia's folly. She made a silly joke... Everybody knows whose son Ronan is... I think he looks like Mia. He's a great guy, by the way.''
We help you decide who to give your money to.
Nature-inspired songs we just can't get enough of.
Artists are coming up with different ways to entertain and help out this year.
Put these British films about music at the top of your watch list.
The Mifo O5 PROs are some of the most durable wireless earbuds on the market and we can't recommend them enough.
These songs were written for times like these.
Live musicians take a financial hit during the worst health crisis of a generation.